text:
Office of Scientific and Technical Information
EMSL: Science: Nanoscience
NLE Websites -- All DOE Office Websites (Extended Search)
Read or print the Nanoscience at EMSL brochure. At EMSL, nanoscience and nanotechnology play a critical, crosscutting role in the mission to integrate experimental and...
Ultrasonic Fatigue of Metals and Alloys I
Science Conference Proceedings (OSTI)
Mar 14, 2012... that combines ultrasonic fatigue instrumentation and Digital Image Correlation ... Closed lock loop control of load amplitude and resonance�...
Modeling Metal Fatigue As a Key Step in PV Module Life Time Prediction (Presentation)
DOE Green Energy (OSTI)
This presentation covers modeling metal fatigue as a key step in photovoltaic (PV) module lifetime predictions. Described are time-dependent and time-independent case studies.
Bosco, N.
Fatigue Behavior of Tough Fe-Based Bulk-Metallic Glasses
A Fracture Mechanics Model of Fatigue Crack Propagation in Bulk-Metallic ... Air- Oxidation of a (Zr55Cu30Al10Ni5)98Er2 Bulk Metallic Glass at 350-500oc.
Brookhaven Nanoscience and Nanomaterials
Nanoscience and Nanomaterials Nanoscience and Nanomaterials The study of nanomaterials-materials on the scale of a nanometer, or a billionth of a meter-is a burgeoning area of study in physics, as well as materials science, chemistry, and biology. This research is an important because many physical and chemical properties of a material change dramatically at the nanoscale. At Brookhaven, physicists collaborate with materials scientists, biologists, and chemists on various nanomaterial research projects. One object under study is the carbon nanotube, a cylindrical carbon structure that is typically a few nanometers wide and can be up to millions of nanometers long. Carbon nanotubes possess exceptional electric and structural properties for their size, making them attractive for many applications. Now, Brookhaven scientists have found one more interesting property: A single nanotube can emit infrared light when a voltage is applied across it, which makes it the world's first electrically controllable light emitter. This research is ongoing, and the scientists hope to find a way to make the nanotube emit visible light.
Argonne CNM Highlight: Nanoscience Student Cooperative
Nanoscience Cooperative for Students Nanoscience Cooperative for Students Nanoscience Collective Students The NanoBusiness Alliance's "Nanoscience High School Talent Fellowship" sponsored 25 students from Illinois, North Carolina and Colorado at Argonne's Center for Nanoscale Materials for one week in June 2010. The NanoBusiness Alliance has partnered with Argonne's Center for Nanoscale Materials (CNM) and Division of Educational Programs (DEP) to better prepare high school juniors and seniors pursuing science and engineering careers. Named the Nanoscience High School Talent Fellowship, the program hosted 25 students from Illinois, North Carolina, and Colorado, who participated in a "boot camp" of hands-on laboratory experiments, demonstrations, and lectures by CNM scientists.
Nano-science Safety Requirements
Nano-science Safety Requirements Effective Date 12/6/2011 Nano-science Safety Requirements Effective Date 12/6/2011 The only official copy of this file is the one on-line. Before using a printed copy, verify that it is the most current version by checking the effective date. Page 1 of 3 Prepared By: L. Stiegler Low Risk - Embedded or Fixed Nanostructures (nanomaterials, incapable as a practical matter, of becoming airborne) Ensure that fixed nanomaterials are not subjected to actions that may generate Unbound NanoParticles (UNP). * For work outside of a HEPA filtered exhaust hood: o No Mechanical stresses e.g., (grinding, scraping, or pressing). o No thermal stresses o Cover samples when practical e.g., (slide cover, Kapton tape, Mylar tape, or cellophane tape). Samples/container must be labeled if not used immediately.
nano-science center kbenhavns universitet
E-Print Network (OSTI)
nano-science center københavns universitet PhD SLAM COMPETITION Can you present your work in three minutes for fellow PhD stu- dents and colleges at Nano-Science Center. Judges from different email@example.com Read more about PhD slam here: nano.ku.dk/Events All are welcome Arranged by: Nano-Science Center
Mosegaard, Klaus
of nanomaterials. Our instrumentation and facilities include: n ELPI n MOUDI n Electron and Scanning Probe Microscopy n Scanning Mobility Particle Sizer n Wide-Range...
Effects of weld metal profile on the fatigue life of integrally reinforced weld-on fittings
SciTech Connect
The cyclic fatigue life of fabricated tee intersections, including integrally reinforced weld-on fittings, has been a topic of discussion in the recent past. The discussion has centered around questions concerning the accuracy of the ASME B31.3 Code equations in calculating the stress intensification factors, (SIFs), for these types of intersection geometries. The SIF of an intersection is an indicator of the fatigue life of the intersection when it is subjected to bending moments caused by thermal, flow, or mechanically induced cyclical displacements. Schneider, Rodabaugh, and Woods concur that inaccuracies in the Code SIF equations do exist and that these equations should be revised. This report presents new Markl type SIF data on the B.W.Pipet (BWP), an integrally reinforced weld-on branch fitting, manufactured by WFI International, Inc., in Houston, Texas. The scope of this research project was to determine the influence of the installation weld metal profile of the Pipet to the run pipe on the SIF. The SIF data were then compared to calculated SIF values using equations from the American Society of Mechanical engineers (ASME) B31.1, ASME B31.3, and ASME Section 3, Subsection NC, for the purpose of determining which Code equation may be the most appropriate for calculating the SIF for these particular fittings.
Woods, G.E. (M.W. Kellogg Co., Houston, TX (United States)); Rodabaugh, E.C. (Rodabaugh (E.C.), Dublin, OH (United States))
Materials characterization of silicon carbide reinforced titanium (Ti/SCS-6) metal matrix composites. Part 1: Tensile and fatigue behavior
Flexural fatigue behavior was investigated on titanium (Ti-15V-3Cr) metal matrix composites reinforced with cross-ply, continuous silicon carbide (SiC) fibers. The titanium composites had an eight-ply (0, 90, +45, {minus}45 deg) symmetric layup. Fatigue life was found to be sensitive to fiber layup sequence. Increasing the test temperature from 24 C to 427 C decreased fatigue life. Interface debonding and matrix and fiber fracture were characteristic of tensile behavior regardless of test temperature. In the tensile fracture process, interface debonding between SiC and the graphite coating and between the graphite coating and the carbon core could occur. A greater amount of coating degradation at 427 C than at 24 C reduced the Ti/SiC interface bonding integrity, which resulted in lower tensile properties at 427 C. During tensile testing, a crack could initiate from the debonded Ti/SiC interface and extend to the debonded interface of the neighboring fiber. The crack tended to propagate through the matrix and the interface. Dimpled fracture was the prime mode of matrix fracture. Interface debonding, matrix cracking, and fiber bridging were identified as the prime modes of fatigue mechanisms. To a lesser extent, fiber fracture was observed during fatigue. However, fiber fracture was believed to occur near the final stage of fatigue failure. In fatigued specimens, facet-type fracture appearance was characteristic of matrix fracture morphology. Theoretical modeling of the fatigue behavior of Ti/SCS-6 composites is presented in Part 2 of this series of articles.
Liaw, P.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Diaz, E.S. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States); Chiang, K.T.; Loh, D.H. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.
Joint Institute for Nanoscience Annual Report 2003
The Joint Institute for Nanoscience (JIN) is a cooperative venture of the University of Washington and Pacific Northwest National Laboratory to encourage and enhance high-impact and high-quality nanoscience and nanotechnology of all types. This first annual report for the JIN summarizes activities beginning in 2001 and ending at the close of fiscal year 2003 and therefore represents somewhat less than two years of activities. Major portions of the JIN resources are dedicated to funding graduate students and postdoctoral research associates to perform research in collaborations jointly directed by Pacific Northwest National Laboratory (PNNL) staff scientists and University of Washington (UW) professors. These fellowships were awarded on the basis of applications that included research proposals. JIN co-sponsors an annual Nanoscale Science and Technology Workshop held in Seattle. In addition to involving PNNL staff in various UW nanoscience courses and seminars, a National Science Foundation grant Development of UW-PNL Collaborative Curriculums in Nano-Science and Technology has allowed the development of three intensive short courses that are taught by UW faculty, PNNL staff, and faculty from other institutions, including Washington State University, the University of Idaho, Stanford University, and the University of Alaska. The initial JIN agreement recognized that expansion of cooperation beyond UW and PNNL would be highly valuable. Starting in early 2003, efforts were initiated to form a regional communication link called the Northwest Nanoscience and Nanotechnology Network (N?). In concept, N? is a tool to encourage communication and help identify regional resources and nanoscience and technology activities.
Baer, Donald R.; Campbell, Charles
Fatigue Weak-Link Density and Strength Distribution in High ...
Symposium, Fatigue and Corrosion Damage in Metallic Materials: Fundamentals, Modeling and Prevention. Presentation Title, Fatigue Weak-Link Density and�...
Joint Institute for Nanoscience Annual Report 2004
Due to the inherently interdisciplinary nature of nanoscience and nanotechnology, research in this arena is often significantly enhanced through creative cooperative activities. The Joint Institute for Nanoscience (JIN) is a venture of the University of Washington (UW) and Pacific Northwest National Laboratory (PNNL) to encourage and enhance high impact and high quality nanoscience and nanotechnology research that leverages the strengths and capabilities of both institutions, and to facilitate education in these areas. This report summarizes JIN award activities that took place during fiscal year 2004 and provides a historical list of JIN awardees, their resulting publications, and JIN-related meetings. Major portions of the JIN efforts and resources are dedicated to funding graduate students and postdoctoral research associates to perform research in collaborations jointly directed by PNNL staff scientists and UW professors. JIN fellowships are awarded on the basis of applications that include research proposals. They have been very successful in expanding collaborations between PNNL and UW, which have led to many excellent joint publications and presentations and enhanced the competitiveness of both institutions for external grant funding. JIN-based interactions are playing a significant role in creating new research directions and reshaping existing research programs at both the UW and PNNL. The JIN also co-sponsors workshops on Nanoscale Science and Technology, four of which have been held in Seattle and one in Richland. In addition to involving PNNL staff in various UW nanoscience courses and seminars, a National Science Foundation grant, Development of UW-PNL Collaborative Curriculums in Nano-Science and Technology, has allowed the development of three intensive short courses that are taught by UW faculty, PNNL staff, and faculty from other institutions, including Washington State University, the University of Idaho, Stanford University, and the University of Alaska. The JIN agreement recognizes that cooperation beyond UW and PNNL is highly valuable. Starting in early 2003, efforts were initiated to form a regional communication link called the Northwest Nanoscience and Nanotechnology Network (N4). In concept, N4 is a tool to encourage communication and help identify regional resources and nanoscience and technology activities.
Fatigue and Corrosion Interaction and Materials Corrosion
Mar 1, 2011 ... Fatigue and Corrosion Damage in Metallic Materials: Fundamentals, ... the high stress ratio corrosion fatigue crack threshold and increases the�...
Sandia National Labs: PCNSC: Research: Nanosciences
Nanosciences Nanosciences Throughout the scientific community, including Sandia National Laboratories (SNL), researchers say building things atom-by-atom or molecule-by-molecule will revolutionize the production of virtually every human-made object. Exciting prospects-but they also point out that the promise of nanotechnology can only be realized if we learn to understand the special rules that control behavior at this small scale and develop the skill needed to integrate these concepts into practical devices. The excitement stems from the understanding that the behavior of materials at the nanoscale is nothing like that at the large scale. The necessary tools, such as powerful new microscopes, have been developed to let researchers see these surprising behaviors. Sandia National Labs'
At EMSL, nanoscience and nanotechnology play a critical, crosscutting...
EMSL, nanoscience and nanotechnology play a critical, crosscutting role in our mission to integrate experimental and computational resources for innovations that support the U.S....
Behavior of a quasi-isotropic ply metal matrix composite under thermo-mechanical and isothermal fatigue loading. Master's thesis
This study investigated the behavior of the SCS6/Ti-15-3 metal matrix composite with a quasi-isotropic layup when tested under static and fatigue conditions. Specimens were subjected to in-phase and out-of-phase thermo-mechanical and isothermal fatigue loading. In-phase and isothermal loading produced a fiber dominated failure while the out-of-phase loading produced a matrix dominated failure. Also, fiber domination in all three profiles was present at higher maximum applied loads and al three profiles demonstrated matrix domination at lower maximum applied loads. Thus, failure is both profile dependent and load equipment. Additional analyses, using laminated plate theory, Halpin-Tsai equations, METCAN, and the Linear Life Fraction Model (LLFM), showed: the as-received specimens contained plies where a portion of the fibers are debonded from the matrix; during fatigue cycling, the 90 deg. plies and a percentage of the 45 deg. plies failed immediately with greater damage becoming evident with additional cycles; and, the LLFM suggests that there may be a non-linear combination of fiber and matrix domination for in-phase and isothermal cycling.
Hart, K.A.
Argonne CNM Highlight: 2007 U.S.-France Nanoscience Workshop
Partnerships in Nanoscience Explored between France and the United States Partnerships in Nanoscience Explored between France and the United States During June 3-5, 2007, a group of 50 researchers and invited participants came together at Argonne National Laboratory for the France-U.S. Nanoscience Workshop. The purpose of this workshop was to help stimulate U.S.-France collaborations in nanoscience. Pat Dehmer, Associate Director for Science, U.S. Department of Energy (DOE), Office of Basic Energy Sciences, attended along with Linda Blevins, Technical and International Advisor. The importance of international collaboration and cooperation for solving critical issues in nanoscience and nanotechnology (e.g., in energy and information technology) was apparent. In yet another demonstration that international partnerships have always been important for the success of DOE laboratory-based research, participants from many of the DOE national laboratories were present.
Materials characterization of silicon carbide reinforced titanium (Ti/SCS-6) metal matrix composites. Part 2: Theoretical modeling of fatigue behavior
Flexural fatigue behavior was investigated on titanium (Ti-15V-3Cr) metal matrix composites reinforced with cross-ply, continuous silicon carbide (SiC) fibers. The titanium composites had an eight-ply (0, 90, +45, {minus}45 deg) symmetric layup. Mechanistic investigation of the fatigue behavior is presented in Part 1 of this series. In Part 2, theoretical modeling of the fatigue behavior was performed using finite element techniques to predict the four stages of fatigue deflection behavior. On the basis of the mechanistic understanding, the fiber and matrix fracture sequence was simulated from ply to ply in finite element modeling. The predicted fatigue deflection behavior was found to be in good agreement with the experimental results. Furthermore, it has been shown that the matrix crack initiation starts in the 90 deg ply first, which is in agreement with the experimental observation. Under the same loading condition, the stress in the 90 deg ply of the transverse specimen is greater than that of the longitudinal specimen. This trend explains whey the longitudinal specimen has a longer fatigue life than the transverse specimen, as observed in Part 1.
Chiang, K.T.; Loh, D.H. [Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.; Liaw, P.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Diaz, E.S. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)
IEEE NANOSCIENCE and TECHNOLOGY BROWN BAG
PLEASE PLEASE JOIN US! NANOSCIENCE and TECHNOLOGY BROWN BAG Friday, 7 November 2008 Noon - 1 pm Columbia River Room (public access available) PNNL, ETB Building (Q Avenue, Richland, WA) speaker Dr. Meyya Meyyappan Chief Scientist for Exploration Technology, NASA Ames Research Center & IEEE Electron Devices Society Distinguished Lecturer presenting Nanotechnology in Chemical and Bio Sensor Systems Abstract: There are strong research programs in nanotechnology related to chemical sensors, electromechanical devices, actuators, biosensors, and other nanodevices in leading laboratories across the world which use nanomaterials and other molecularly-engineered approaches. In many cases, practical systems demand seamless integration of the nanodevice with higher order structures, for example, MEMS. Examples of this using carbon nanotube based chemical and biosensors
020 Post-Impact Fatigue of Short Kenaf Fibre Metal Laminates
053 Polymer-Derived Mesoporous SiOC/ZnO Nanocomposite for Water Decontamination ... 064 Synthesis and Study of the Chemical Interaction of Strontium .... 163 The Mechanism of Metallic Iron Aggregation and Effect of Addition Agent on�...
Microsoft Word - France-US Nanoscience agenda_FINAL.doc
France - U.S. Nanoscience Workshop France - U.S. Nanoscience Workshop Argonne National Laboratory June 3-5, 2007 APS 401, Room A1100 SUNDAY, June 3 7:30 Bus departures begin from Argonne Guest House (APS 401 is also in walking distance) 8:00-9:00 Registration in APS Atrium 8:00-9:00 Continental Breakfast Welcome and Introduction 9:00 Welcome to Argonne Eric Isaacs 9:10 DOE Overview Pat Dehmer 9:40 CNRS Overview Didier Stiévenard and Alain Fontaine "Center of Competence of Nanosciences in France" 10:00 CEA Overview Jean-Philippe Bourgoin 10:15 Break Electronic and Magnetic Properties Eric Isaacs, Presiding 10:30 Bruno Grandidier (IEMN, CNRS, Lille) "Linewidths in Tunneling Spectroscopy of Semiconducting Nanocrystals" 11:00 Philippe Guyot Sionnest (University of Chicago)
Office of Scientific and Technical Information (OSTI)
FATIGUE DESIGN CURVES FATIGUE DESIGN CURVES FOR 6061-T6 ALUMINUM* G . T . Yahr Engineering Technology Division Oak Ridge National Laboratory Oak Ridge, Tennessee 37831-8051 ABSTRACT A request has been made to the ASME Boiler and Pressure Vessel Committee that 6061-T6 aluminum be approved for use in the construction of Class 1 welded nuclear vessels so it can be used for the pressure vessel of the Advanced Neutron Source research reactor. Fatigue design curves with and without mean stress effects have been proposed. A knock-down factor of two is applied to the design curve for evaluation of welds. The basis of the curves is explained. The fatigue design curves are compared to fatigue data from base metal and weldments. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States
New Asphaltene Nanoscience and Its Impact on Reservoir Characterization
Asphaltene Nanoscience and Its Impact on Asphaltene Nanoscience and Its Impact on Reservoir Characterization Oliver C. Mullins Schlumberger-Doll Research, 1 Hampshire St., Cambridge, MA 02139, USA Crude oils consist of gases, liquids and solids, the asphaltenes. The gas and liquid constituents of crude oil are chemically well understood and their theoretical frame work can be satisfactorily treated by cubic equations of state. In contrast, the asphaltene have been grossly misunderstood precluding any theoretical treatment of asphaltene gradients in reservoirs. In recent years, asphaltene science has undergone a renaissance with many of the advances being subsumed in the "Yen-Mullins model" (named by Professor Zare at Stanford U.) which consists of asphaltene molecules, nanoaggregates and clusters of
Muon Application to Advanced Bio- and Nano-Sciences
Among present and future applications of the muon to various fields of sciences, there are several examples where research accomplishments can only be done by using muons. Here we would like to explain the selected two examples representing bio- and nano-sciences, namely, muon spin imaging of human brain for new brain function studies and muonium spin-exchange scattering spectroscopy for the development of spintronics materials.
Nagamine, Kanetada [Muon Science Laboratory, KEK, Tsukuba, Ibaraki, 305-0081 (Japan); Atomic Physics Laboratory, RIKEN, Wako, Saitama, 351-0198 (Japan); Department of Physics and Astronomy, University of California, Riverside, CA92521 (United States)
Nanoscience Images from the Center for Nanophase Materials Sciences (CNMS)
DOE Data Explorer (OSTI)
DOE's Nanoscale Science Research Centers to support the synthesis, processing, fabrication, and analysis of materials at the nanoscale are also National User Facilities. The Center for Nanophase Materials Science is currently one of five ceterns for interdisciplinary research at the nanoscale. These centers are laboratories for nanofabrication, may have one-of-a-kind signature instruments, including nanopatterning tools and research-grade probe microscopes. The images produced by nanoscience research and the technologies involved are beautiful and unique. This website makes available a very small collection but very high quality, public domain images
Effect on the condition of the metal in A K-300-3.5 turbine owing to multicycle fatigue from participation of a power generating unit in grid frequency and power regulation
The effect on the condition of the rotor material owing to multicycle fatigue caused by variable stresses during participation of a power generating unit in grid frequency and power regulation is evaluated using the K-300-23.5 steam turbine as an example. It is shown that during normalized primary frequency regulation the safety factor is at least 50, while during automatic secondary regulation of frequency and power there is essentially no damage to the metal.
Lebedeva, A. I.; Zorchenko, N. V.; Prudnikov, A. A.
Effect of Microstructure and Grain Size on Fatigue Properties of ...
Abstract Scope, Passive metals exposed to fatigue and wear in corrosive ... In order to investigate multi-degradation, an in-house developed lab scale test rig�...
Final technical report for DOE Computational Nanoscience Project: Integrated Multiscale Modeling of Molecular Computing Devices
This document reports the outcomes of the Computational Nanoscience Project, "Integrated Multiscale Modeling of Molecular Computing Devices". It includes a list of participants and publications arising from the research supported.
Cummings, P. T.
Grain size effects on the fatigue response of nanocrystalline materials
The resistance of metals and alloys to fatigue crack initiation and propagation is known to be influenced significantly by grain size. Based on a wealth of experimental results obtained from microcrystalline metals, where ...
Hanlon, Timothy, 1977-
Theory and modeling in nanoscience: Report of the May 10-11, 2002Workshop
On May 10 and 11, 2002, a workshop entitled ''Theory and Modeling in Nanoscience'' was held in San Francisco, California, sponsored by the offices of Basic Energy Science and Advanced Scientific Computing Research of the Department of Energy. The Basic Energy Sciences Advisory Committee and the Advanced Scientific Computing Advisory Committee convened the workshop to identify challenges and opportunities for theory, modeling, and simulation in nanoscience and nanotechnology, and additionally to investigate the growing and promising role of applied mathematics and computer science in meeting those challenges. This report is the result of those contributions and the discussions at the workshop.
McCurdy, C. William; Stechel, Ellen; Cummings, Peter; Hendrickson, Bruce; Keyes, David
Aircraft Corrosion Fatigue Assessment
...Fatigue in the Presence of Corrosion, Proc., NATO Research and Technology Organization Meeting (Corfu,
High cycle fatigue and fatigue crack propagation behavior of ...
And fatigue crack propagation rates of modified A7075 showed slightly lower. Those superior fatigue strength and resistance of fatigue crack propagation of�...
Fatigue and Fatigue Crack Propagation Behaviors of High ...
The S-N fatigue and fatigue crack propagation (FCP) behaviors of high ... The mechanisms associated with the improved fatigue resistance for the high�...
Fatigue Phenomena in Metallic Materials
Table 1 Types of variable-amplitude tests and main variables...simulation tests Variable of service load history to be simulated OL, overload...
Was There a Nano-fiction Before There Was a Nano-science? Anticipations of
1 Was There a Nano-fiction Before There Was a Nano-science? Anticipations of Nanotechnology Is Nano About Nano? Nanotechnology is "development of single-atom layer gizmos that can replicate), 18 June 2003, Features; Times2, 18. Nanotechnology "is nano-sized particles and structures made from
Gaeta, Alexander L.
Fatigue of Nanocrystalline Materials and Fatigue Property ...
Mar 1, 2011 ... Effects of Ultrasonic Nanocrystal Surface Modification on Fatigue Behavior of SUS316 Austenitic Stainless Steel Tube for Stents: Auezhan�...
Fatigue Testing of Carbon Steels and Low-Alloy Steels [Corrosion...
Fatigue Testing of Carbon Steels and Low-Alloy Steels Capabilities Materials Testing Environmentally Assisted Cracking (EAC) of Reactor Materials Corrosion PerformanceMetal...
Nanoscience to nanotechnology for civil engineering: proof of concepts
Conventional concrete improved by applying nanotechnology aims at developing a novel, smart, eco- and environment- friendly construction material towards the green structure. In today's life, though utilization of cement based materials plays a vital ... Keywords: challenges, chemical reaction, civil application, construction materials, crystalline, metal oxide, nano science, nano technology, natural minerals
B. Bhuvaneshwari; Saptarshi Sasmal; Nagesh R. Iyer
Partnering Today: Technology Transfer Highlights Metal ...
The compressive stress signi?cantly increases the metal part�s resistance to cracking or corrosion. By extending fatigue lifetimes, laser
Fatigue Life Data
...It has long been recognized that fatigue data, when resolved into elastic and plastic terms, can be represented as linear functions of life on a logarithmic scale. Figure 41 schematically shows this representation of elastic and plastic components, which together define the total fatigue life...
Stress-Based Fatigue Monitoring
The FatiguePro software, developed by the Electric Power Research Institute (EPRI) and first deployed in 1989, is a fatigue monitoring program that is widely used around the world to assist with aging management of nuclear power plants. The FatiguePro stress-based fatigue (SBF) module has used a single stress term for calculating fatigue usage factors. This simplified approach was chosen not only because of computer limitations at the time, but also because the conventional stress cycle counting algorith...
Fatigue Property Enhancement and Life Prediction
Mar 6, 2013 ... Fatigue in Materials: Microstructure-Driven Modeling and In-Situ Fatigue Characterization: Fatigue Property Enhancement and Life Prediction
Dwell Fatigue Design Criteria - Programmaster.org
Energy Based Fatigue Life Prediction Models and Methods for Combined Low Cycle and High Cycle Fatigue � Fatigue Behavior of AM60B Subjected to Variable �...
Dekker Encyclopedia of Nanoscience and Nanotechnology, 2nd edition, 6 volumes set
PREFACE TO SECOND EDITION The science of the ultra small nanoscience has dramatically exploded during the last few years, and the technologies operating with ultra small things the nanotechnologies acquired quickly a firm position in today s world of business, technological development, and public perception. Several factors contributed to the acceleration of scientific knowledge and technological progress in the last decades, among which the rapid development of fast computers, availability of high-resolution analytical techniques, and the progress of molecular biology and genetics are probably the most important. The result was an unprecedented expansion of the frontiers of science, which empowered the human genius with unlimited options of top-down and bottom-up methods for manipulation of materials structure and control of properties at multiple levels, from atomic to molecular, supramolecular, and biomolecular. Already a distinctive mark of 21st century, nanoscience and nanotechnology will certainly have a steadily increasing influence on the quality of life and the environment of this Planet for centuries to come. Dekker Encyclopedia of Nanoscience and Nanotechnology, Second Edition provides a comprehensive and detailed review, from multiple angles, of major developments in the human s quest for understanding and mastering of physical, chemical and biological objects and structures having at least one dimension smaller than about 100 nm. Under the expert supervision of the late Professor James A. Schwarz, Marcel Dekker, Inc. published the first edition in 2004 to great acclaim. The success of first edition, the development of the title through online updates, and the dynamics of this continuously growing field has created a high demand for a second edition only four years after the first edition. The second edition offers updated and revised entries, along with many additions that reflect the focus towards energy and environmental issues currently in the news. The new edition is expanded to six volumes. All entry titles have been revised to better reflect to the entry's content, while optimized for alphabetical listing. In addition, a comprehensive (though not exhaustive) topical table of contents has been designed, structured on 24 major topics and almost 100 subtopics. With a robust and efficient indexing system and staggered bleed tabs, this second print edition will be a useful reference tool for scientists in academia and national laboratories, engineers, students, as well as entrepreneurs, policy makers, and opinion builders. The online version of the Encyclopedia offers quick access to individual entries in HTML or PDF format, enriched graphical content, hundreds of color illustrations and photographs, and an efficient keyword search engine. Cristian I. Contescu Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA Karol Putyera Shiva Technologies, Syracuse, New York, USA July 2008
Contescu, Cristian I [ORNL] [ORNL; Putyera, Karol [Shiva Technologies, Syracuse NY] [Shiva Technologies, Syracuse NY
Fatigue Resistance of Carbon Nanotube Reinforced Aluminum ...
Presentation Title, Fatigue Resistance of Carbon Nanotube Reinforced Aluminum ... Fatigue crack propagation (FCP) and fracture mechanism of Al-CNT �...
A Summary of the Fatigue Properties of Wind Turbine Materials
Modern wind turbines are fatigue critical machines that are typically used to produce electrical power from the wind. The materials used to construct these machines are subjected to a unique loading spectrum that contains several orders of magnitude more cycles than other fatigue critical structures, e.g., an airplane. To facilitate fatigue designs, a large database of material properties has been generated over the past several years that is specialized to materials typically used in wind turbines. In this paper, I review these fatigue data. Major sections are devoted to the properties developed for wood, metals (primarily aluminum) and fiberglass. Special emphasis is placed on the fiberglass discussion because this material is current the material of choice for wind turbine blades. The paper focuses on the data developed in the U.S., but cites European references that provide important insights.
Functional neuroimaging of circadian fatigue
Along with the increase of demanding mental effort work, sleep loss, extended work period, mental fatigue is a very common phenomenon in everyday modern life. Recently, mental fatigue has been receiving increasing attention from military, transport, ...
Xiaoping Li; Bui Ha Duc
Effects of light water reactor coolant environment on the fatigue lives of
Effects of light water reactor coolant environment on the fatigue lives of Effects of light water reactor coolant environment on the fatigue lives of reactor materials July 8, 2013 A metal component can become progressively degraded, and its structural integrity can be adversely impacted when it is subjected to repeated fluctuating loads, or fatigue loading. Fatigue loadings on nuclear reactor pressure vessel components can occur because of changes in pressure and temperature caused by transients during operation, such as reactor startup or shutdown and turbine trip events. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code recognizes fatigue as a possible cause of failure of reactor materials and provides rules for designing nuclear power plant components to avoid fatigue failures. For various materials, the ASME Code defines the
Fatigue and Creep-Fatigue Deformation of an Ultra-Fine Precipitate Strengthened Advanced Austenitic Alloy
An advanced austenitic alloy, HT-UPS (high-temperature ultrafine-precipitation-strengthened), has been identified as an ideal candidate material for the structural components of fast reactors and energy-conversion systems. HT-UPS alloys demonstrate improved creep resistance relative to 316 stainless steel (SS) through additions of Ti and Nb, which precipitate to form a widespread dispersion of stable nanoscale metallic carbide (MC) particles in the austenitic matrix. The low-cycle fatigue and creep-fatigue behavior of an HT-UPS alloy have been investigated at 650 �C and a 1.0% total strain, with an R-ratio of -1 and hold times at peak tensile strain as long as 150 min. The cyclic deformation response of HT-UPS is directly compared to that of standard 316 SS. The measured values for total cycles to failure are similar, despite differences in peak stress profiles and in qualitative observations of the deformed microstructures. Crack propagation is primarily transgranular in fatigue and creep-fatigue of both alloys at the investigated conditions. Internal grain boundary damage in the form of fine cracks resulting from the tensile hold is present for hold times of 60 min and longer, and substantially more internal cracks are quantifiable in 316 SS than in HT-UPS. The dislocation substructures observed in the deformed material differ significantly; an equiaxed cellular structure is observed in 316 SS, whereas in HT-UPS the microstructure takes the form of widespread and relatively homogenous tangles of dislocations pinned by the nanoscale MC precipitates. The significant effect of the fine distribution of precipitates on observed fatigue and creep-fatigue response is described in three distinct behavioral regions as it evolves with continued cycling.
M.C. Carroll; L.J. Carroll
Fatigue-crack propagation behavior of Inconel 718
The techniques of linear-elastic fracture mechanics were used to characterize the effect of several variables (temperature, environment, cyclic frequency, stress ratio, and heat-treatment variations) upon the fatigue-crack growth behavior of Inconel 718 base metal and weldments. Relevant crack growth data on this alloy from other laboratories is also presented. (33 fig, 39 references) (auth)
James, L.A.
Surface Treatment to Increase Metal Fatigue Life
An easy, safe, inexpensive, and low environmental impact surface-treatment has been ... First-Principles Calculation of Finite Temperature APB Energies in the�...
Microstructure-Property-Fatigue Deformation & Damage Relationships
Mar 5, 2013 ... Combining DIC and Ultrasonic Fatigue to Investigate the Very High Cycle Fatigue Behavior of Ti-6242: Jason Geathers1; J. Wayne Jones1;�...
Ultrasonic Fatigue Testing System Combined with Nondestructive ...
Presentation Title, Ultrasonic Fatigue Testing System Combined with ... High and Very High Cycle Fatigue in Al and Cu Thin Films on Si Substrate.
Ultrasonic Fatigue of Advanced Materials and Systems
Combining Ultrasonic Fatigue with Synchrotron X-radiograhy and in situ Nonlinear ... High and Very High Cycle Fatigue in Al and Cu Thin Films on Si Substrate.
Fatigue of Materials III
... workers and engineers from academia, industry and research laboratories. ... spectrum of metals, intermetallics, ceramics and their composite counterparts.
Characterization of Fatigue Crack Propagation in a Haynes 230 ...
The High Cycle Fatigue, Damage Initiation and Growth and Final ...
Evaluation of Thermal Fatigue Effects on Systems Requiring Aging Management Review for License Renewal for the Calvert Cliffs Nuclear Power Plant
In recent years, the nuclear power industry has devoted significant attention to metal fatigue and its impact on the design qualification and serviceability of operating components. This study provides a pilot plant demonstration of the current industry technical position on fatigue evaluation for license renewal, specifically addressing reactor water environmental effects. It also develops a technical evaluation method for determining fatigue life adequacy in a feedwater piping system, a pressurizer sur...
Steam Generator Management Program: Generic Elements of U-Bend Tube Vibration Induced Fatigue Analysis for Westinghouse Model F Steam Generators
U-bend tube ruptures due to metal fatigue have been experienced by several utilities worldwide. The first fatigue-related tube rupture occurred at North Anna Unit 1 in�1987. The knowledge gained from this event provides the basis for estimating the potential for a fatigue failure in other plants. This report provides the generic information for a Westinghouse Model F steam generator, and defines the information required to complete a plant-specific u-bend analysis to determine susceptibility to ...
Fatigue and Corrosion
Mar 6, 2013 ... The ease of processing combined with exceptional strength and toughness .... demands a strict control of the local electrochemical dissolution process based ... Initial cell adhesion and viability, cell proliferation, differentiation, and ... provide high dispersion and effective utilization of the active noble metal.
A Dynamic Reversal Bending Fatigue Testing System
A bending fatigue system has been proposed and developed in this disclosure to test various structural materials in general.
Fatigue in Advanced Materials & Environmental Effects
Mar 6, 2013 ... Local variations in crack growth rate, investigations of fatigue crack .... the first step consists in conduct a finite element analysis in order to�...
Parameters Controlling the Thermal Fatigue Properties of ...
component thermal fatigue lifetimes ... with a symmetrical cycle shape maintained for the heating and cooling ... to the surfaces of components to enhance. E o.
Crystallographic Orientation Dependence of Fatigue Crack ...
In the present study, fatigue crack propagation behavior of rolled AZ31B magnesium ... Alloy Design for Enhancing the Fracture Resistance of Heat Treated High�...
Role of crack tip shielding in the initiation and growth of long and small fatigue cracks in composite microstructures
The role of crack tip shielding in retarding the initiation and growth of fatigue cracks has been examined in metallic composite microstructures (consisting of hard and soft phases), with the objective of achieving maximum resistance to fatigue. Specifically, duplex ferritic-martensitic structures have been developed in AISI 1008 and 1015 mild steels to promote shielding without loss in strength. The shielding is developed primarily from crack deflection and resultant crack closure, such that unusually high long crack propagation resistance is obtained. It is found that the fatigue threshold ..delta..K/sub TH/ in AISI 1008 can be increased by more than 100 pct to over 20 MPa ..sqrt..m, without sacrifice in strength, representing the highest ambient temperature threshold reported for a metallic alloy to date. Similar but smaller increases are found in AISI 1015. The effect of the dual-phase microstructures on crack initiation and small crack (10 to 1000 ..mu..m) growth, however, is markedly different, characteristic of behavior influenced by the mutual competition of intrinsic and extrinsic (shielding) ''toughening'' mechanisms. Accordingly, the composite microstructures which appear to show the highest resistance to the growth of long cracks, show the lowest resistance to crack initiation and small crack growth. In general, dual-phase steels are found to display remarkable fatigue properties, with fatigue limits as high as 58 pct of the tensile strengths and fatigue thresholds in the range of 13 to 20 MPa..sqrt..m.
Shang, J.K.; Tzou, J.L.; Ritchie, R.O. (Materials and Chemical Sciences Div., Lawrence Berkeley Lab., and Dept. of Materials Science and Mineral Engineering, Univ. of California, Berkeley, CA (US))
Fatigue Behavior in Monocrystalline Ni-Based Superalloys for Blade ...
fatigue resistance, resulting in the need to better understand the effects of alloy microstructure on fatigue crack initiation and propagation. In this study, sustained �...
Effect of Interstitial Content on High Temperature Fatigue Crack ...
instance; resulted in fatigue crack propagation (FCP)' programs like ESDADTA(2) and ENSIP(3). Fatigue resistance of nickel base superalloys is affected by�...
Processing and mechanical properties of high temperature/high performance composites. Fatigue and creep. Book 3. Annual report, 1 March 1992-28 February 1994
This document includes the following topics; (1) Mode I fatigue cracking in a fiber reinforced metal matrix composite; (2) Interfacial crack growth in fiber-reinforced metal-matrix composites; (3) Fatigue crack growth in fiber-reinforced metal-matrix composites; (4) Thermomechanical fatigue cracking in fiber reinforced metal matrix composites; (5) Transverse and cyclic thermal loading of the fiber reinforced metal-matrix composite SCS6/Ti-15-3; (6) Fatigue of ceramic matrix composite; (7) Ductile-reinforcement toughening in gamma gamma/TiAl intermetallic-matrix composites; effects on fracture toughness and fatigue-crack propagation resistance; (8) Creep models for metal matrix composites with long brittle fibers; (9) Models for the creep of ceramic matrix composite materials; (10) Power law creep of ceramic matrix composite materials; (10) Power law creep with interface slip and diffusion in a composite material; (11) Steady state creep of fiber-reinforced composites: Constitutive equations and computational issues; (12) The creep anisotropy of a continuous-fiber-reinforced SiC/CAS composite; (13) Power law creep of a composite material containing discontinuous rigid aligned fibers; and (14) Diffusive void bifurcation in stressed solid.
Evans, A.G.; Leckie, F.A.
On the Fatigue Analysis of Wind Turbines
Modern wind turbines are fatigue critical machines that are typically used to produce electrical power from the wind. Operational experiences with these large rotating machines indicated that their components (primarily blades and blade joints) were failing at unexpectedly high rates, which led the wind turbine community to develop fatigue analysis capabilities for wind turbines. Our ability to analyze the fatigue behavior of wind turbine components has matured to the point that the prediction of service lifetime is becoming an essential part of the design process. In this review paper, I summarize the technology and describe the ''best practices'' for the fatigue analysis of a wind turbine component. The paper focuses on U.S. technology, but cites European references that provide important insights into the fatigue analysis of wind turbines.
Sutherland, Herbert J.
Accelerating Fatigue Testing for Cu Ribbon Interconnects (Presentation)
This presentation describes fatigue experiments and discusses dynamic mechanical loading for Cu ribbon interconnects.
Bosco, N.; Silverman, T.; Wohlgemuth , J.; Kurtz, S.; Inoue, M.; Sakurai, K.; Shioda, T.; Zenkoh, H.; Miyashita, M.; Tadanori, T.; Suzuki, S.
Modeling Thermal Fatigue in CPV Cell Assemblies (Presentation)
This presentation outlines the modeling of thermal fatigue in concentrating photovoltaic (CPV) assemblies.
Bosco, N.; Panchagade, D.; Kurtz, S.
Optimal Railroad Rail Grinding for Fatigue Mitigation
This dissertation aims to study the benefit of rail grinding on service life of railroad rails, focusing on failures due to rolling contact fatigue (RCF) at the rail head. Assuming a tangent rail with one-point contact at the running surface, a finite element analysis of a full-scale wheel-rail rolling contact with a nonlinear isotropic kinematic hardening material model is performed to simulate the accumulation of residual stresses and strains in the rail head. Using rolling stress and strain results from the sixth loading cycle, in which residual stresses and strains are at their steady-state, as input, two critical plane fatigue criteria are proposed for fatigue analyses. The first fatigue criterion is the stress-based approach�namely the Findley fatigue criterion. It suggests an important role of tensile residual stresses on subsurface crack nucleation and early growth in the rail head, but applications of the criterion to the near-running-surface region are limited because of plastic deformation from wheel-rail contact. The second fatigue criterion is the strain-based approach�namely the Fatemi-Socie fatigue criterion. Contributed mainly from shear strain amplitudes and factorized by normal stress components, the criterion also predicts fatigue crack nucleation at the subsurface as a possible failure mode as well as fatigue crack nucleation at the near-surface, while maintaining its validity in both regions. A collection of fatigue test data of various types of rail steel from literature is analyzed to determine a relationship between fatigue damages and number of cycles to failure. Considering a set of wheel loads with their corresponding number of rolling passage as a loading unit (LU), optimizations of grinding schedules with genetic algorithm (GA) show that fatigue life of rail increases by varying amount when compared against that from the no-grinding case. Results show that the proposed grinding schedules, optimized with the exploratory and local-search genetic algorithms, can increase fatigue life of rail by 240 percent. The optimization framework is designed to be able to determine a set of optimal grinding schedules for different types of rail steel and different contact configurations, i.e. two-point contact occurred when cornering.
Tangtragulwong, Potchara
Probabilistic fatigue methodology and wind turbine reliability
Wind turbines subjected to highly irregular loadings due to wind, gravity, and gyroscopic effects are especially vulnerable to fatigue damage. The objective of this study is to develop and illustrate methods for the probabilistic analysis and design of fatigue-sensitive wind turbine components. A computer program (CYCLES) that estimates fatigue reliability of structural and mechanical components has been developed. A FORM/SORM analysis is used to compute failure probabilities and importance factors of the random variables. The limit state equation includes uncertainty in environmental loading, gross structural response, and local fatigue properties. Several techniques are shown to better study fatigue loads data. Common one-parameter models, such as the Rayleigh and exponential models are shown to produce dramatically different estimates of load distributions and fatigue damage. Improved fits may be achieved with the two-parameter Weibull model. High b values require better modeling of relatively large stress ranges; this is effectively done by matching at least two moments (Weibull) and better by matching still higher moments. For this purpose, a new, four-moment {open_quotes}generalized Weibull{close_quotes} model is introduced. Load and resistance factor design (LRFD) methodology for design against fatigue is proposed and demonstrated using data from two horizontal-axis wind turbines. To estimate fatigue damage, wind turbine blade loads have been represented by their first three statistical moments across a range of wind conditions. Based on the moments {mu}{sub 1}{hor_ellipsis}{mu}{sub 3}, new {open_quotes}quadratic Weibull{close_quotes} load distribution models are introduced. The fatigue reliability is found to be notably affected by the choice of load distribution model.
Lange, C.H. [Stanford Univ., CA (United States)
The High Cycle Fatigue and Final Fracture Behavior of Alloy Steel ...
Figure: ...as open symbols, whereas cyclic conditions that led to fracture at <10 7 cycles are represented with closed symbols. The 10 7 cycle
Evaluation of weldment creep and fatigue strength-reduction factors for elevated-temperature design
New explicit weldment strength criteria in the form of creep and fatigue strength-reduction factors were recently introduced into the American Society of Mechanical Engineers Code Case N-47, which governs the design of elevated-temperature nuclear plants components in the United States. This paper provides some of the background and logic for these factors and their use, and it describes the results of a series of long-term, confirmatory, creep-rupture and fatigue tests of simple welded structures. The structures (welded plates and tubes) were made of 316 stainless steel base metal and 16-8-2 weld filler metal. Overall, the results provide further substantiation of the validity of the strength-reduction factor approach for ensuring adequate life in elevated-temperature nuclear component weldments. 16 refs., 7 figs.
Corum, J.M.
Cryogenic Treatment of Metal Parts
Cryogenic treatment and its variables have been described. Results of eight engineering tests carried out on cryotreated parts have been presented. Cryogenic treatment of metal parts enhances useful properties which in turn, improves various strengths. Our tests viz. Abrasion, Torsion, Fatigue, Tensile, Shear, Hardness and Impact on Mild steel, Cast Iron, Brass and Copper show that the cryogenic treatment improved useful properties of mild steel parts appreciably but did not show promise with brass and copper parts.
Chillar, Rahul [S. P. College of Engineering, Andheri (W), Mumbai - 400 058 (India); Agrawal, S. C. [Tata Institute of Fundamental Research, Colaba, Mumbai - 400 005 (India)
Designing Oceanographic Surface Moorings to Withstand Fatigue
A method is presented for predicting the fatigue resistance of a single-point oceanographic mooring. The method determines the fraction of life that the components of a mooring lose during a deployment by combining results of dynamic analysis, ...
Mark A. Grosenbaugh
High Cycle Fatigue of ULTIMET Alloy
curves of this alloy regardless of the testing frequencies and environments. At 20 Hz ... The availability of fatigue data in ULTIMET alloy will provide new commercial .... perchloric, 90 ml distilled water, and 100 ml butylcellosolve was used for�...
Conductor fatigue life research. Final report
Objective of this Phase II work was to experimentally evaluate the long-term effectiveness of amplitude reductions in arresting the aeolian fatigue deterioration of minimally damaged ACSR conductors supported in standard short-radius suspension clamps. The aeolian vibration was simulated by mechanical means in a controlled laboratory situation and the reduction in vibration amplitudes was a simulation of the addition of amplitude limiting devices (dampers). Conductors were vibrated at high amplitudes until a predetermined number of strand breaks occurred, after which the vibration was continued at reduced amplitudes. The Phase II research expanded the number of cycles of vibration and amplitude reduction values for the conductors used in the Phase I effort. The results indicated that the amplitude reductions arrested long-term fatigue strand breaks in every case tested. Additionally, the maximum fatigue damage arrestment amplitude was expanded and evaluated to be 20 mils at the 3-1/2 inch location for Drake ACSR conductor. Electric utilities can utilize the results of this EPRI project in assessing the fatigue life of minimally damaged transmission lines and in evaluating techniques for mitigating fatigue damage. A secondary objective of the Phase II effort was to develop aeolian vibration Load-N curves (dynamic bending stress versus number of cycles of vibration curves) for some ACSR conductors based on Ontario-Hydro recorder and wind data. The wind data generated Load-N curves developed appear to be too conservative. The modified worst-case Ontario-Hydro recorder Load-N curve developed is recommended as a design guideline curve for aeolian fatigue troubled lines in Georgia. The development and use of Load-N curves in conjunction with S-N curves are required for rational aeolian fatigue design of overhead conductors, and for estimating line fatigue lives.
Ramey, G.E.
PNNL: Nanoscience and Nanotechnology
on Surfaces Prepared Using Soft Landing of Mass Selected Ions," featured in ACS Nano. EMSL News See the latest news highlights from EMSL. Contact Us Don Baer Web...
Temporal Instabilities and Dissipative Structures in Fatigued Metals
In our simulations we always assumed for simplicity that m = 2. The effective stress can be related to the applied stress in eqn. (6) in the following simple way,
Fatigue and Corrosion Damage in Metallic Materials: Fundamentals ...
Jul 31, 2011 ... Organizer(s), Tongguang Zhai, University of Kentucky Zhengdong Long, Kaiser Aluminum Peter Liaw, University of Tennessee. Scope, This�...
Fracture and Fatigue of Metallic Glass Matrix Composites
Lignocellulosic-Based Carbon Fibers from Biofuel Production Wastes � Magnesium Sheets Produced by Extrusion � Magnetite Formation Observed with TEM on�...
Failure by fracture and fatigue in "NANO" and "BIO" materials
AND FATIGUE IN �NANO� AND �BIO� MATERIALS R. O. Ritchie, 1,3and Fatigue in �Nano� and �Bio� Materials R. O. Ritchie 1 ,structures and biologi- cal/bio-implantable materials, so-
Ritchie, R.O.; Muhlstein, C.L.; Nalla, R.K.
FATIGUEPRO: On-Line Fatigue Usage Transient Monitoring System
FATIGUEPRO accurately monitors plant data to calculate actual fatigue usage for critical nuclear plant components. This system should improve plant reliability and contribute to plant life extension by providing a more realistic estimation of fatigue demands.
Metal Aminoboranes
Metal aminoboranes of the formula M(NH.sub.2BH.sub.3).sub.n have been synthesized. Metal aminoboranes are hydrogen storage materials. Metal aminoboranes are also precursors for synthesizing other metal aminoboranes. Metal aminoboranes can be ...
High Cycle Fatigue in a Single Crystal Superalloy: Time ...
Keywords: Single crystal superalloys, High cycle fatigue, Environmental coatings, Rupture ... modes were modeled separately and then combined into a damage.
On the Fatigue Crack Propagation Behavior of Superalloys at ...
ON THE FATIGUE CRACK PROPAGATION BEHAVIOR. OF SUPERALLOYS AT ... the FCP resistance of superalloys ... lead to poor crack propagation behavior.
Fatigue reliability of wind turbine components
Fatigue life estimates for wind turbine components can be extremely variable due to both inherently random and uncertain parameters. A structural reliability analysis is used to qualify the probability that the fatigue life will fall short of a selected target. Reliability analysis also produces measures of the relative importance of the various sources of uncertainty and the sensitivity of the reliability to each input parameter. The process of obtaining reliability estimates is briefly outlined. An example fatigue reliability calculation for a blade joint is formulated; reliability estimates, importance factors, and sensitivities are produced. Guidance in selecting distribution functions for the random variables used to model the random and uncertain parameters is also provided. 5 refs., 9 figs., 1 tab.
Veers, P.S.
Fatigue of Wind Blade Laminates:Fatigue of Wind Blade Laminates: Effects of Resin and Fabric Structure
Fatigue of Wind Blade Laminates:Fatigue of Wind Blade Laminates: Effects of Resin and Fabric University MCARE 2012 #12;Outline · Overview of MSU Fatigue Program on Wind Blade MaterialsWind Blade Wind Blade Component Materials Acknowledgements: Sandia National Laboratories/DOE (Joshua Paquette
Estimates of thermal fatigue due to beam interruptions for an ALMR-type ATW
Thermal fatigue due to beam interruptions has been investigated in a sodium cooled ATW using the Advanced Liquid Metal mod B design as a basis for the subcritical source driven reactor. A k{sub eff} of 0.975 was used for the reactor. Temperature response in the primary coolant system was calculated, using the SASSYS- 1 code, for a drop in beam current from full power to zero in 1 microsecond.. Temperature differences were used to calculate thermal stresses. Fatigue curves from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code were used to determine the number of cycles various components should be designed for, based on these thermal stresses.
Dunn, F. E.; Wade, D. C.
Quantifying the Thermal Fatigue of CPV Modules
A method is presented to quantify thermal fatigue in the CPV die-attach from meteorological data. A comparative; study between cities demonstrates a significant difference in the accumulated damage. These differences are most; sensitive to the number of larger (?T) thermal cycles experienced for a location. High frequency data (<1/min) may; be required to most accurately employ this method.
Bosco, N.; Kurtz, S.
Putting a price on worker fatigue
In a round-the-clock industry such as mining, extended work hours may be necessary for production but damaging to the bottom line. A recent report commissioned by the Minerals Council of Australia (MCA) attempts to document the relationship between sleep, working arrangements and fatigue. The study, titled Work Design, Fatigue and Sleep by Dr. Angela Baker and Dr. Sally Ferguson of the Australian Center for Sleep Research at the University of South Australia contains information useful for managing fatigue in the workplace. The publication is available free online at http://www.minerals.org.au. The study offers guidelines for planing work schedules or for chaning shifts. William G. Sirosis, senior vice president and COO of Circadian Technologies Inc., also addressed this topic in a presentation at the recent MineWest 2006 conference. He pointed out that the exact dollar costs of operating with a fatigued workforce was difficult to pinpoint but the cumulative effect can be damaging to a company's production and profitability. He suggested steps to a successful management programme.
Carter, R.A.
Fatigue behavior and recommended design rules for an automotive composite
Fatigue curves (stress vs cycles to failure) were generated under a variety of conditions (temperatures, fluid environments, mean stresses, block loadings) for a candidate automotive structural composite. The results were used to (1) develop observations regarding basic fatigue behavioral characteristics and (2) establish fatigue design rules. The composite was a structural reaction injection-molded polyurethane reinforced with continuous strand, swirl-mat E-glass fibers. Tensile fatigue tests on specimens from a single plaque at {minus}40 F, room temperature, and 250 F provided the basic behavioral characteristics. It was found that when stress was normalized by the at-temperature ultimate tensile strength, the fatigue curves at the three temperatures collapsed into a single master curve. An assessment of the individual stress-strain loops throughout each test showed a progressive loss in stiffness and an increase in permanent strain, both of which are indicative of increasing damage. Fatigue tests on specimens from several plaques were used to develop a design fatigue curve, which was established by using a reduction factor of 20 on average cycles to failure. This factor assures that the stiffness loss during the design life is no greater than 10 percent. Fatigue reduction factors were established to account for various fluids. Reversed stress fatigue tests allowed a mean stress rule to be validated, and block loading tests were used to demonstrate the adequacy of Miner`s rule for cumulative fatigue damage.
Corum, J.M.; Battiste, R.L.; Ruggles, M.B.
Lasershot peening--a means to strengthen metals
Lasershot peening is an emerging modern process that impresses a compressive stress into the surfaces of metals, improving their operational lifetime. Almost everyone is familiar with taking a strip of metal or a wire and bending it multiple times until it breaks. In this situation, when the metal is bent, the surface of outer radius is stretched into a tensile state. Under tension, any flaw or micro-crack will grow in size with each bending of the metal until the crack grows through the entire strip, breaking it into two pieces. Flexure of metal components occurs in most applications. The teeth of a transmission gear flex as they deliver torque in a vehicle. Springs and valves flex every time they transfer loads. If fatigue failure from flexing occurs in the tooth of a transmission gear of light or heavy vehicles, in a fan blade of a diesel engine, in shock-absorbers or safety-related supporting structures, significant loss of assets and potentially loss of human life occurs. Lasershot peening, better than any other technique, has the potential to extend the fatigue lifetime of metal components. In the process, the laser generates a high intensity shock wave at the surface of the metal, straining the metal and leaving a residual compressive stress. If the compressive stress is intense and deep enough, when the gear tooth or component flexes under load, the surface remains in compression and a micro-crack or flaw on the surface cannot grow. Test data on gears are showing lifetime improvements up to 6 times. Tests on structural aluminum components, such as used in the transportation vehicle are showing 10 to 15 times lifetime improvement. As shown in the Figure below, recent fatigue tests on 2024 T3 aluminum under various stress load conditions, show more than 50 times improvement in fatigue lifetime for structural aluminum test plates when compared to unpeened components and 10 times when compared to conventionally shot-peened components.
Chen, H-L
Metal Aminoboranes Metal Aminoboranes Metal Aminoboranes Metal aminoboranes of the formula M(NH.sub.2BH.sub.3).sub.n have been synthesized. June 25, 2013 Metal Aminoboranes Metal aminoboranes of the formula M(NH.sub.2BH.sub.3).sub.n have been synthesized. Available for thumbnail of Feynman Center (505) 665-9090 Email Metal Aminoboranes Metal aminoboranes of the formula M(NH.sub.2BH.sub.3).sub.n have been synthesized. Metal aminoboranes are hydrogen storage materials. Metal aminoboranes are also precursors for synthesizing other metal aminoboranes. Metal aminoboranes can be dehydrogenated to form hydrogen and a reaction product. The reaction product can react with hydrogen to form a hydrogen storage material. Metal aminoboranes can be included in a kit. U.S. Patent No.: 7,713,506 (DOE S-112,798)
General Assessment of Various Types of Fatigue Fracture ...
Abstract Scope, Fatigue cracking accounts for ~90% of service related events encountered in modern gas turbine engine components and must be addressed in�...
Fatigue Predictions of Various Joints of Magnesium Alloys
Currently, a front shock tower of passenger vehicle is developed with various magnesium alloys and joining methods. To predict the fatigue behavior of the joints�...
Fundamentals of Fatigue Damage and Modeling - Programmaster.org
Feb 28, 2011 ... Fatigue Weak-Link Density and Strength Distribution in High Strength Al Wrought and Cast Alloys: Tongguang Zhai1; Yuanbin Zhang2;�...
High Temperature Fatigue Behavior of Laser Shock Peened ...
Presentation Title, High Temperature Fatigue Behavior of Laser Shock Peened IN718Plus Superalloy. Author(s), Vibhor Chaswal, S R Mannava, Dong Qian,�...
Influence of Microstructure on Fatigue Properties of Alloy 718
combination of the various phases that may be present in the microstructure. ... smooth and notch high cycle fatigue behavior at room temperature and 650�C is �...
Sustained Peak Low Cycle Fatigue: The Role of Coatings
The growth process continued by a combined process of oxidation and creep. ... of a model developed for crack growth during sustained peak low cycle fatigue.
An Energy-Based Microstructure Model to Account for Fatigue ...
A Quantitative Crystallographic Model for Fatigue Crack Propagation through ... Effect of Temperature on The Loss of Ductility of S-135 Grade Drill Pipe Steel�...
High Cycle Fatigue Behavior of Shot-Peened Steels
High Temperature Corrosion Fatigue and Grain Size Control in ...
diesel engines and so on, are inevitably subjected to the simultaneous effects of both the mechanical damages such as creep and/or fatigue and the corrosive.
Thermal fatigue evaluation of solder alloys. Final report
An evaluation was made of the relative thermal fatigue resistance of 29 solder alloys. A number of these alloys were found to be less susceptible to thermal fatigue cracking in encapsulated printed wiring board applications than the commonly used tin-lead eutectic (63Sn-37Pb). Three alloys, 95Sn-5Ag, 96.5Sn-3.5Ag, and 95Sn-5Sb offered the greatest resistance to thermal fatigue. The selection of the encapsulation materials was confirmed to be a significant factor in thermal fatigue of solder joints, regardless of the solder alloy used.
Jarboe, D.M.
Characterization of Elevated Temperature Fatigue Crack Growth Rates
temperature fatigue and the crack growth rates may be adequately correlated with the ... During creep crack growth the use of rate dependent elastic/plastic frac-.
Treatment effects of the Forsus fatigue resistant device.
??Objectives: To evaluate the correction obtained from the Forsus Fatigue Resistant (FRD) device and orthodontic appliances compared to an untreated control group. Methods: Twenty four� (more)
Heinrichs, Dean.
Fatigue and Microstructure: A Symposium on Recent Advances
Symposium, Fatigue and Microstructure: A Symposium on Recent Advances. Sponsorship, MS&T Organization. Organizer(s), Amit Shyam, Oak Ridge National �...
Low-Cycle Fatigue Properties of TRIP Steel
Oct 15, 2006 ... AHSS typically have improved fatigue strength over conventional steels and High Strength Steels (HSS) of similar tensile strength. Sample�...
Tension and Flex Bending Fatigue of Superelastic Nitinol
Symposium, Shape Memory Alloys. Presentation Title, Tension and Flex Bending Fatigue of Superelastic Nitinol. Author(s), John R Lewandowski, Brian Benini,�...
Fatigue Crack Initiation in Alloy 718 at 650 C
gas turbine engine discs, the loss in fatigue life is less severe. ... rotating components such as discs, spacers and cooling plates in gas turbine engines during.
Effects of Ultrasonic Nanocrystal Surface Modification on Fatigue ...
Presentation Title, Effects of Ultrasonic Nanocrystal Surface Modification on Fatigue Behavior of SUS316 Austenitic Stainless Steel Tube for Stents. Author(s) �...
Comparison of Fatigue and Fracture Properties of Nb- and V ...
In structural applications that are exposed to the environment,? ?such as bridges,? ? wind towers,? ?power transmission towers,? ?even tall buildings,? ?good fatigue�...
Fourth International Conference on Very High Cycle Fatigue
Jul 18, 2007 ... Peter K. Liaw, The University of Tennessee, USA. �Fatigue ..... Must-see artifacts include the Lincoln Chair, Kennedy Presidential. Limousine�...
Corrosion Fatigue and Crack Propagation of Different Austenitic ...
A FIB Study of the Resistance of Grain Boundaries to Short Fatigue Crack Propagation in Three-Dimensions in High Strength Al Alloys � A Non-Linear Damage�...
Enhanced Corrosion Fatigue Resistance of AISI304 Bellows ...
Effect of Thermal-Mechanical Treatment on the Fatigue Crack ...
that fatigue crack propagation (FCP) resistance without holding time has no significant difference between three alloys with 718Plus being the best and 718 the�...
Fatigue Property-Microstructure Relationships and Crack Growth
Feb 28, 2011 ... Effect of Microstructure on Fatigue Behavior of Two Pipeline Steels: .... to a transition crack length (LEFM applicable) is approximated using�...
Structural Changes During Thermal Fatigue of Two Nickel-Based ...
greatly affect the thermal endurance of these heat-resisting alloys. I?. ... factors govern- ing the thermal fatigue behavior of a number of commercial nickel-.
Fatigue Behavior of AM60B Subjected to Variable Amplitude Loading
Currently, a front shock tower of passenger vehicle is developed with various magnesium alloys. To predict the fatigue behavior of the structure, fatigue�...
Cyclic Deformation and Fatigue Cracking Mechanisms of F.C.C. ...
Fatigue Crack Tip Mechanics Following a Tensile Overload � Fatigue Weak-Link Density and Strength Distribution in High Strength Al Wrought and Cast Alloys.
Dynamic muscle fatigue detection using self-organizing maps
Wavelets are used for the processing of signals that are non-stationary and time varying. The electromyogram (EMG) contains transient signals related to muscle activity. Wavelet coefficients are proposed as features for identifying muscle fatigue. By ... Keywords: Biomedical signal processing, Comfort, EMG, Muscle fatigue, Neural networks, Self-organizing maps, Transient signal, Visualization, Wavelets
Dimitrios Moshou; Ivo Hostens; George Papaioannou; Herman Ramon
Conductor fatigue-life research. Final report
This is the final report of Research Project RP 1278-1 sponsored by the Electric Power Research Institute and carried out at the Civil Engineering Department of Auburn University (Auburn, Alabama). The objective of this study was to evaluate the effects of reducing vibration amplitudes of ACSR conductors which had been minimally damaged by aeolian vibration. The aeolian vibration was simulated by mechanical means in a controlled laboratory situation and the reduction in vibration amplitudes was a simulation of the addition of amplitude limiting devices (dampers). Conductors were vibrated at high amplitudes until a predetermined number of strand breaks occurred, after which the vibration was continued at reduced amplitudes. Three different ACSB conductors were tested: 795 KCM 26/7, 795 KCM 45/7, and 397.5 KCM 26/7. These conductors were chosen to establish the effects of conductor size and stranding on the amplitude reduction tests. Two different amplitude reductions were used to establish a threshold value for a maximum reduced amplitude. Previous preliminary research by others indicated that amplitude reductions extended the working life of conductors. This research expanded the amplitude reduction values and conductor sizes and strandings tested. For each set of parameters, four duplicative tests were performed to give statistical credence to the data. The results of the investigation indicated that amplitude reductions arrested fatigue strand breakage in each case. Electric utilities can utilize the results of this EPRI project in assessing the fatigue life of minimally damaged transmisson lines and in evaluating techniques for mitigating fatigue damage.
Multi-Agent Model for Fatigue Control in Large Offshore Wind Farm
To control wind turbine fatigue and optimize the fatigue distribution for offshore wind farm, a control network model is proposed based on Multi-Agent theory. A typical model of large-scale offshore wind farm is described. Power fatigue of individual ... Keywords: Multi-Agent model, fatigue, wind turbine, offshore wind farm
Rongyong Zhao; Yongqing Su; Torben Knudsen; Thomas Bak; WenZhong Shen
Compression-Compression Fatigue Investigation of a ...
K. K. Chawla's Seminal Contributions to the Field of Metal Matrix Composites � Structural Health Monitoring of Wind Turbine Blades � Studies of Nanocrystalline �...
Fatigue case study and reliability analyses for wind turbines
Modern wind turbines are fatigue critical machines used to produce electrical power. To insure long term, reliable operation, their structure must be optimized if they are to be economically viable. The fatigue and reliability projects in Sandia`s Wind Energy Program are developing the analysis tools required to accomplish these design requirements. The first section of the paper formulates the fatigue analysis of a wind turbine using a cumulative damage technique. The second section uses reliability analysis for quantifying the uncertainties and the inherent randomness associated with turbine performance and the prediction of service lifetimes. Both research areas are highlighted with typical results.
Sutherland, H.J.; Veers, P.S.
Light Metals
Alternative processes; Anode design and operation; Cell fundamentals and ... Hot-rolling technologies; Deformation of materials; Primary metal production.
Accelerated Fatigue Crack Growth Behavior of PWA 1480 Single ...
3 456. 610. 1520 30. AK . AKrss. MPa v'?! Fig. 10 Fatigue crack growth rate as a function of AKrss and AK. Prediction of the Microscopic Crack Behavior: An�...
Effect of Heat Treatment on Fatigue Behavior and Mechanical ...
The effect of heat treatment on the rotating beam fatigue strength of .... E9: Effect of Shot Peening on Bending Strength of AZ31 Magnesium Alloy Pipe � Effect of�...
Corrosion Fatigue Crack Growth and Stress-Corrosion Cracking in ...
Abstract Scope, The high stress ratio (R=0.85) corrosion fatigue crack growth kinetics and stress-corrosion cracking resistance of sensitized (70-175 �C up to�...
Nanoscience Research Internships in Illinois
NanoBusiness Talent Project Summary Report The NanoBusiness Alliance created the NanoBusiness Talent Program to ensure the future vitality of domestic scientists and entrepreneurs by engaging advanced high school students in cutting-edge nanotechnology development. This program commenced on September 1, 2008 and ran through August 31, 2010 with a very successful group of students. Several of these students went on to Stanford, Harvard and Yale, as well as many other prestigious Universities. We were able to procure the cooperation of several companies over the entire run of the program to voluntarily intern students at their companies and show them the possibilities that exist for their future. Companies ranged from NanoInk and Nanosphere to QuesTek and NanoIntegris all located in northern Illinois. During the 9-week internships, students worked at nanotechnology companies studying different ways in which nanotechnology is used for both commercial and consumer use. The students were both excited and invigorated at the prospect of being able to work with professional scientists in fields that previously may have just been a dream or an unreachable goal. All the students worked closely with mentors from each company to learn different aspects of procedures and scientific projects that they then used to present to faculty, parents, mentors and directors of the program at the end of each year�s program. The presentations were extremely well received and professionally created. We were able to see how much the students learned and absorbed through the course of their internships. During the last year of the program, we reached out to both North Carolina and Colorado high school students and received an extraordinary amount of applications. There were also numerous companies that were not only willing but excited at the prospect to engage highly intelligent high school students and to encourage them into the nanotechnology scientific field. Again, this program increase was highly received and the students were thoroughly engaged. Our program ended August 31, 2010 with our last class of students and their final presentations. From the pilot year to the end presentations, we received hundreds of applications from students excited for the opportunity to work in a scientific field. With our goal of inspiring the newest generation of potential scientists and mathematician, we not only found ourselves overwhelmingly impressed but encouraged that the greatest minds of the future will come from this next generation and many more generations.
Kronshage, Alisa [Executive Board
PNNL: Nanoscience and Nanotechnology -Facilities
of Energy Search PNNL Search PNNL Home About Research Publications Jobs News Contacts Nano banner DOE Nanoscale Science Research Centers Argonne National Laboratory (Center for...
Guidelines for Addressing Environmental Effects in Fatigue Usage Calculations
Requirements by the U.S. Nuclear Regulatory Commission (NRC) to address reactor water environmental effects on fatigue of class 1 reactor pressure boundary components in license renewal evaluations and for new plants have led to the development of American Society of Mechanical Engineers (ASME) Code Cases designed to provide rules for such evaluations. This report describes the results of efforts by industry participants to complete two sample fatigue evaluations according to the rules of ASME Code ...
Vibration Fatigue of Small Bore Socket-Welded Pipe Joints
In the course of developing the screening process for the EPRI Fatigue Management Handbook, TR-104534, several areas were identified in which the industry's understanding of socket welds was somewhat lacking and current ASME Code procedures were inadequate to accurately characterize their high-cycle fatigue resistance. The research described in this report is directed at improving the understanding of socket welds and the factors and parameters that affect a socket weld's ability to resist vibration-indu...
Program 87: Proceedings of the EPRI International Creep-Fatigue Experts Workshop 5: ASTM ;EPRI Creep-Fatigue Interaction Symposium
The industrial need for extended service life of power generation plants calls for assessing the creep-fatigue performance of traditional boiler and turbine components. This is particularly important for structural integrity and safe operation of units designed for base load operation. The Electric Power Research Institute (EPRI) leads an international experts group, including key industry experts and researchers, for Experts Workshop on Creep-Fatigue Damage Interaction, which is held annually.
Colloid Science of Metal Nanoparticle Catalysts in 2D and 3D Structures. Challenges of Nucleation, Growth, Composition, Particle Shape, Size Control and their Influence on Activity and Selectivity
Recent breakthroughs in synthesis in nanosciences have achieved control of size and shapes of nanoparticles that are relevant for catalyst design. In this article, we review the advance of synthesis of nanoparticles, fabrication of two and three dimensional model catalyst system, characterization, and studies of activity and selectivity. The ability to synthesize monodispersed platinum and rhodium nanoparticles in the 1-10 nm range permitted us to study the influence of composition, structure, and dynamic properties of monodispersed metal nanoparticle on chemical reactivity and selectivity. We review the importance of size and shape of nanoparticles to determine the reaction selectivity in multi-path reactions. The influence of metal-support interaction has been studied by probing the hot electron flows through the metal-oxide interface in catalytic nanodiodes. Novel designs of nanoparticle catalytic systems are discussed.
Somorjai, Gabor A.; Park, Jeong Y.
Precious Metals
"Advances in the Extractive Metallurgy of Selected Rare and Precious Metals" ( 1991 Review of Extractive Metallurgy), J.E. Hoffmann, April 1991, pp. 18-23.
Environmentally Assisted Fatigue Gap Analysis and Roadmap for Future Research: Gap Analysis Report
Over the past two decades, there has been growing recognition of the effects of light water reactor (LWR) environments on fatigue initiation life and fatigue crack growth in nuclear power plant components, and environmentally assisted fatigue (EAF) has emerged as a significant issue affecting assessments to justify component lifetimes. Generally speaking, revised assessments are likely to predict reduced fatigue life and enhanced crack growth rates, as compared to corresponding predictions ...
Materials Reliability Program: Lessons Learned from PWR Thermal Fatigue Management Training (MRP-83)
In January 2001, The EPRI Materials Reliability Program (MRP) issued an Interim Guideline (MRP-24) for the management of thermal fatigue in non-isolable piping attached to reactor coolant piping in pressurized water reactor (PWR) plants (EPRI report 1000701). To assist utility personnel in understanding the potential for thermal fatigue in this piping, the MRP also conducted plant-specific workshops at plant sites. These workshops offered training on fatigue and fatigue cracking in non-isolable piping, a...
Materials Reliability Program: Thermal Fatigue Monitoring Guidelines (MRP-32, Revision 1)
This report provides thermal fatigue monitoring guidelines for attached piping systems in which there might be high potential for thermal fatigue cracking. The Materials Reliability Program (MRP) has published guidance under the Nuclear Energy Institute (NEI) 03-08 materials initiative for addressing potential thermal fatigue cycling in non-isolable reactor coolant system branch lines. This guidance calls for monitoring, inspection, and/or fatigue analysis of susceptible lines.
Materials Reliability Program (MRP-149, Revision 1) Fatigue Licensing Basis Monitoring Guideline
All nuclear plants are required to operate their mechanical systems within the parameters defined by fatigue design basis requirements, analyses and assumptions. This monitoring guideline is part of the Electric Power Research Institute�s (EPRI�s) comprehensive and integrated Fatigue Management approach designed to prevent and/or manage cracking of components due to fatigue.BackgroundThis document provides guidance for utility engineers to implement a fatigue ...
Fatigue case study and loading spectra for wind turbines
The paper discusses two aspects of Sandia`s Wind Energy Program. The first section of the paper presents a case study of fatigue in wind turbines. This case study was prepared for the American Society of Testing Material`s (ASTM) Standard Technical Publication (STP) on fatigue education. Using the LIFE2 code, the student is lead through the process of cumulative damage summation for wind turbines and typical data are used to demonstrate the range of life estimates that will result from typical parameter variations. The second section summarizes the results from a workshop held by Sandia and the National Renewable Energy Laboratory (NREL) to discuss fatigue life prediction methodologies. This section summarizes the workshop discussions on the use of statistical modeling to deduce the shape and magnitude of the low-probability-of-occurrence, high-stress tail of the load distribution on a wind turbine during normal operation.
Sutherland, H.J.
A General Method for Fatigue Analysis of Vertical Axis
The fatigue life of wind turbine blades that are exposed to the random loading environment of atmospheric winds is described with random data analysis procedures. The incident wind speed and the stresses caused by these winds are expressed in terms of probability density functions, while the fatigue life vs stress level relationship is treated deterministically. This approach uses a "damage density function" to express fatigue damage as a function of wind speed. By examining the constraints on the variables in the damage density expression, some generalizations of the wind turbine fatigue problem are obtained. The area under the damage density function is inversely related to total fatigue life. Therefore, an increase in fatigue life caused by restricted operation in certain wind regimes is readily visualized. An "on parameter", which is the percentage of total time at each wind speed that the turbine actually operates, is introduced for this purpose. An example calculation is presented using data acquired from the DOE 100-kW turbine program. *This work was performed at Sandia National Laboratories and was supported by the US Department of Energy under Contract Number DE-AC04-76DP00789. Acknowledgments The calculations required to produce the figures in this paper would not have been possible without the work of Jerry McNerney and Tim Leonard in developing the AUTOSYM computer simulation, The efforts of Nolan Clark and Ron Davis in collecting data for the DOE 100-kW turbine at the USDA station in Bushland, TX are greatly appreciated. of Vertical Axis Wind Turbine Blades
Paul S. Veers
Mechanisms for fatigue and wear of polysilicon structural thinfilms
Fatigue and wear in micron-scale polysilicon structural films can severely impact the reliability of microelectromechanical systems (MEMS). Despite studies on fatigue and wear behavior of these films, there is still an on-going debate regarding the precise physical mechanisms for these two important failure modes. Although macro-scale silicon does not fatigue, this phenomenon is observed in micron-scale silicon. It is shown that for polysilicon devices fabricated in the MUMPs foundry and SUMMiT process stress-lifetime data exhibits similar trends in ambient air, shorter lifetimes in higher relative humidity environments and no fatigue failure at all in high vacuum. Transmission electron microscopy of the surface oxides of the samples show an approximate four-fold thickening of the oxide at stress concentrations after fatigue failure, but no thickening after fracture in air or after fatigue cycling in vacuo. It is found that such oxide thickening and fatigue failure (in air) occurs in devices with initial oxide thicknesses of {approx}4-20 nm. Such results are interpreted and explained by a reaction layer fatigue mechanism; specifically, moisture-assisted subcritical cracking within a cyclic stress-assisted thickened oxide layer occurs until the crack reaches a critical size to cause catastrophic failure. Polysilicon specimens from the SUMMiT process are used to study wear mechanisms in micron-scale silicon in ambient air. Worn parts are examined by analytical scanning and transmission electron microscopy, while temperature changes are monitored using infrared microscopy. These results are compared with the development of values of static coefficients of friction (COF) with number of wear cycles. Observations show amorphous debris particles ({approx}50-100 nm) created by fracture through the silicon grains ({approx}500 nm), which subsequently oxidize, agglomerate into clusters and create plowing tracks. A nano-crystalline layer ({approx}20-200 nm) forms at worn regions. No dislocations or extreme temperature increases are found, ruling out plasticity and temperature-assisted mechanisms. The COF reaches a steady-state value of {approx}0.20{+-}0.05 after a short time at an initial value of {approx}0.11{+-}0.01. Plowing tracks are found before the steady-state value of the COF is reached, suggesting only a short adhesive wear regime. This suggests a predominantly abrasive wear mechanism, controlled by fracture, which commences by the first particles created by adhesive wear.
Alsem, Daniel Henricus
Modeling Thermal Fatigue in CPV Cell Assemblies: Preprint
A finite element model has been created to quantify the thermal fatigue damage of the CPV die attach. Simulations are used to compare to results of empirical thermal fatigue equations originally developed for accelerated chamber cycling. While the empirical equations show promise when extrapolated to the lower temperature cycles characteristic of weather-induced temperature changes in the CPV die attach, it is demonstrated that their damage does not accumulate linearly: the damage a particular cycle contributes depends on the preceding cycles. Simulations of modeled CPV cell temperature histories provided for direct comparison of the FEM and empirical methods, and for calculation of equivalent times provided by standard accelerated test sequences.
Bosco, N.; Silverman, T. J.; Kurtz, S.
Effects of LWR coolant environments on fatigue lives of austenitic stainless steels
The ASME Boiler and Pressure Vessel Code fatigue design curves for structural materials do not explicitly address the effects of reactor coolant environments on fatigue life. Recent test data indicate a significant decrease in fatigue life of pressure vessel and piping materials in light water reactor (LWR) environments. Fatigue tests have been conducted on Types 304 and 316NG stainless steel in air and LWR environments to evaluate the effects of various material and loading variables, e.g., steel type, strain rate, dissolved oxygen (DO) in water, and strain range, on fatigue lives of these steels. The results confirm the significant decrease in fatigue life in water. The environmentally assisted decrease in fatigue life depends both on strain rate and DO content in water. A decrease in strain rate from 0.4 to 0.004%/s decreases fatigue life by a factor of {approx} 8. However, unlike carbon and low-alloy steels, environmental effects are more pronounced in low-DO than in high-DO water. At {approx} 0.004%/s strain rate, reduction in fatigue life in water containing <10 ppb D is greater by a factor of {approx} 2 than in water containing {ge} 200 ppb DO. Experimental results have been compared with estimates of fatigue life based on the statistical model. The formation and growth of fatigue cracks in austenitic stainless steels in air and LWR environments are discussed.
Chopra, O.K.; Gavenda, D.J. [Argonne National Lab., IL (United States). Energy Technology Div.
Fatigue of Composite Materials and Substructures for Wind Turbine Blades
This report presents the major findings of the Montana State University Composite Materials Fatigue Program from 1997 to 2001, and is intended to be used in conjunction with the DOE/MSU Composite Materials Fatigue Database. Additions of greatest interest to the database in this time period include environmental and time under load effects for various resin systems; large tow carbon fiber laminates and glass/carbon hybrids; new reinforcement architectures varying from large strands to prepreg with well-dispersed fibers; spectrum loading and cumulative damage laws; giga-cycle testing of strands; tough resins for improved structural integrity; static and fatigue data for interply delamination; and design knockdown factors due to flaws and structural details as well as time under load and environmental conditions. The origins of a transition to increased tensile fatigue sensitivity with increasing fiber content are explored in detail for typical stranded reinforcing fabrics. The second focus of the report is on structural details which are prone to delamination failure, including ply terminations, skin-stiffener intersections, and sandwich panel terminations. Finite element based methodologies for predicting delamination initiation and growth in structural details are developed and validated, and simplified design recommendations are presented.
Probabilistic fatigue damage prognosis using maximum entropy approach
al., 1979). Therefore, fatigue damage accumulation is stochastic in nature. Several physical models, parameter estimation and future inspection and maintenance need to be carefully included for risk assessment studies have been reported to combine the information obtained from inspection with the physical model
Liu, Yongming
Fatigue crack growth estimation by relevance vector machine
The investigation of damage propagation mechanisms on a selected safety-critical component or structure requires the quantification of its remaining useful life (RUL) to verify until when it can continue performing the required function. In this work, ... Keywords: Bayesian techniques, Fatigue crack growth, Prognostics, Relevance vector machine, Residual useful life, Support vector machine
Enrico Zio; Francesco Di Maio
The Development of Confidence Limits for Fatigue Strength Data
Over the past several years, extensive databases have been developed for the S-N behavior of various materials used in wind turbine blades, primarily fiberglass composites. These data are typically presented both in their raw form and curve fit to define their average properties. For design, confidence limits must be placed on these descriptions. In particular, most designs call for the 95/95 design values; namely, with a 95% level of confidence, the designer is assured that 95% of the material will meet or exceed the design value. For such material properties as the ultimate strength, the procedures for estimating its value at a particular confidence level is well defined if the measured values follow a normal or a log-normal distribution. Namely, based upon the number of sample points and their standard deviation, a commonly-found table may be used to determine the survival percentage at a particular confidence level with respect to its mean value. The same is true for fatigue data at a constant stress level (the number of cycles to failure N at stress level S{sub 1}). However, when the stress level is allowed to vary, as with a typical S-N fatigue curve, the procedures for determining confidence limits are not as well defined. This paper outlines techniques for determining confidence limits of fatigue data. Different approaches to estimating the 95/95 level are compared. Data from the MSU/DOE and the FACT fatigue databases are used to illustrate typical results.
Polymer quenched prealloyed metal powder
DOE Patents (OSTI)
A powder metallurgical process of preparing a sheet from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The sheet can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.0.05% Zr .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Ni, .ltoreq.0.75% C, .ltoreq.0.1% B, .ltoreq.1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, and/or .ltoreq.3 % Cu. The process includes forming a non-densified metal sheet by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or plasma spraying, forming a cold rolled sheet by cold rolling the non-densified metal sheet so as to increase the density and reduce the thickness thereof and annealing the cold rolled sheet. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the sheet can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired sheet thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled sheet recrystallizes to an average grain size of about 10 to 30 .mu.m. Final stress relief annealing can be carried out in the B2 phase temperature range.
Hajaligol, Mohammad R. (Midlothian, VA); Fleischhauer, Grier (Midlothian, VA); German, Randall M. (State College, PA)
Alloys of uranium which are strong, hard, and machinable are presented, These alloys of uranium contain bctween 0.1 to 5.0% by weight of at least one noble metal such as rhodium, palladium, and gold. The alloys may be heat treated to obtain a product with iniproved tensile and compression strengths,
Seybolt, A.U.
Thermostat Metals
...A thermostat metal is a composite material (usually in the form of sheet or strip) that consists of two or more materials bonded together, of which one can be a nonmetal. Because the materials bonded together to form the composite differ in
Thermal Cycling on Fatigue Failure of the Plutonium Vitrification Melter
One method for disposition of excess plutonium is vitrification into cylindrical wasteforms. Due to the hazards of working with plutonium, the vitrification process must be carried out remotely in a shielded environment. Thus, the equipment must be easily maintained. With their simple design, induction melters satisfy this criterion, making them ideal candidates for plutonium vitrification. However, due to repeated heating and cooling cycles and differences in coefficients of thermal expansion of contacting materials fatigue failure of the induction melter is of concern. Due to the cost of the melter, the number of cycles to failure is critical. This paper presents a method for determining the cycles to failure for an induction melter by using the results from thermal and structural analyses as input to a fatigue failure model.
Jordan, Jeffrey; Gorczyca, Jennifer
Fatigue Enhancement of a Carbon Fiber Reinforced Nanocomposite
The primary objective of the present investigation is to study the fatigue characteristics of a woven carbon fiber reinforced polymer which has been modified with either amine or fluorine functionalized carbon nanotubes on the fiber-matrix interface. Multi-wall functionalized carbon nanotubes are sprayed onto both sides of each fiber at 0.2-wt % with respect to the fibers. The composites are fabricated using high temperature vacuum assisted resin transfer molding with four-harness satin weave fabric and EPON 862/Epi-Kure W epoxy. Due to the heterogeneous nature of carbon fiber composites, under dynamic loading the composites undergoes a series of complex failure mechanisms: matrix cracking, fiber-matrix debonding, fiber fracture, and buckling. It is believed that debonding of the fiber-matrix interface is the most crucial of these failure mechanisms. Debonding of the fiber-matrix interface critically hinders the matrix�s ability to transfer loads to the fibers, leading to a poor distribution of load. Due to this distribution, one of three failures occurs: individual yarns of fibers are overloaded and fracture, the matrix losses strength and buckles, or a mixture of the two occurs. It will be shown that functionalized multi-wall carbon nanotubes can strengthen the fiber-matrix interface, resulting in fatigue life improvement. The research investigates this behavior for both tension-tension and tension-compression fatiguing. It is believed that improvements will be best at negative R-ratios and high cycle regimes, because the damage is almost entirely matrix dominated occurs under these conditions. Results have shown improvements in static tensile properties of about twenty percent and an order of magnitude improvement in the fatigue life. Fractographic analysis reveals that the nanocomposites can withstand far greater matrix damage prior to final failure. In addition, both optical and scanning electron microscopy indicates that the nanocomposite exhibits reduced fiber-matrix debonding.
Wilkerson, Justin W.
Program on Technology Innovation: The State-of-Knowledge Report on Creep-Fatigue Interaction
This report is part of an ongoing Electric Power Research Institute (EPRI) initiative to review and document the current state of knowledge regarding creep-fatigue. Industry experts have assessed and documented current creep-fatigue test methods, evaluated analytical and life-prediction methodologies, assessed deficiencies in the current understanding and prediction of creep-fatigue damage, and identified issues for future research and development.
Plant Component Assessment for Creep-Fatigue Damage: Component Assessment Methodologies
This report is part of an ongoing Electric Power Research Institute (EPRI) project to document the current state of knowledge and to address the creep-fatigue assessment of components. An international group of industry and academic experts led by EPRI has assessed and documented creep-fatigue evaluation, analytical and life prediction methodologies, and deficiencies in the current understanding and prediction of creep-fatigue damage. This led to the identification of issues for future research and devel...
Program on Technology Innovation: Proceedings of the Expert Workshop on Creep-Fatigue Damage Interaction
As utilities adopt operating practices that involve more severe cycles, it becomes increasingly important to assess the creep-fatigue performance of traditional boiler and turbine components. EPRI brought together key industry experts for the Expert Workshop on Creep-Fatigue Damage Interaction to: Assess and document current creep-fatigue test methods Evaluate analytical methodologies with respect to crack initiation and growth Discuss life prediction methodologies for different applications Assess defi...
Energy Conservation in Metals
About this Symposium. Meeting, 2010 TMS Annual Meeting & Exhibition. Symposium, Energy Conservation in Metals. Sponsorship, The Minerals, Metals and�...
Effect of Aging Treatment on Fatigue Behavior of an Al-Cu-Mg-Ag Alloy
Tests were performed to characterize the distribution in fatigue lifetimes at a given stress level and the small-crack growth behavior under the two aging�...
Fatigue Resistance of Al-Cu-Li and Comparison with 7xxx ...
We have studied the fatigue resistance of alloys 2050 (AlCuLi alloy belonging to the AIRWARETM family) and 7050. Crack initiation and propagation have been�...
A High-Sensitivity Fiber-Optic Sensor for Fatigue Testing
Presentation Title, A High-Sensitivity Fiber-Optic Sensor for Fatigue Testing. Author(s), Nguyen Q Nguyen, Nikhil Gupta. On-Site Speaker (Planned), Nikhil Gupta.
Leave-in-Place Laser Scanning for Fatigue Damage Monitoring and ...
Mechanical Behavior in Human Cortical Bone Across Multiple Length Scales: ... Hydrogen-Accelerated Fatigue Crack Growth in a Low-Strength Pipeline Steel.
Effect of Cooling Rate on the Fatigue Life of a Nickel-Base ...
Presentation Title, Effect of Cooling Rate on the Fatigue Life of a Nickel-Base ... The Zinagizado Processes as New Electrochemical Alternative to Prevent the�...
Fatigue and Creep Properties of Al-Si Brazing Filler Metals
Jun 5, 2012 ... The manufacturing process for automotive heat exchangers involves brazing using an aluminum brazing sheet. To ensure structural strength�...
The Effect of Applied Pressure During Feeding of Critical Cast Aluminum Alloy Components With Particular Reference to Fatigue Resistance
the medium to long freezing range alloys of aluminum such as A356, A357, A206, 319 for example are known to exhibit dispersed porosity, which is recognized as a factor affecting ductility, fracture toughness, and fatigue resistance of light alloy castings. The local thermal environment, for example, temperature gradient and freezing from velocity, affect the mode of solidification which, along with alloy composition, heat treatment, oxide film occlusion, hydrogen content, and the extent to which the alloy contracts on solidification, combine to exert strong effects on the porosity formation in such alloys. In addition to such factors, the availability of liquid metal and its ability to flow through the partially solidified casting, which will be affect by the pressure in the liquid metal, must also be considered. The supply of molten metal will thus be controlled by the volume of the riser available for feeding the particular casting location, its solidification time, and its location together with any external pressure that might be applied at the riser.
J.T. Berry; R. Luck; B. Zhang; R.P. Taylor
Mechanochemical processing for metals and metal alloys
A set of processes for preparing metal powders, including metal alloy powders, by ambient temperature reduction of a reducible metal compound by a reactive metal or metal hydride through mechanochemical processing. The reduction process includes milling reactants to induce and complete the reduction reaction. The preferred reducing agents include magnesium and calcium hydride powders. A process of pre-milling magnesium as a reducing agent to increase the activity of the magnesium has been established as one part of the invention.
Froes, Francis H. (Moscow, ID); Eranezhuth, Baburaj G. (Moscow, ID); Prisbrey, Keith (Moscow, ID)
Successful development of metallic filters with high temperature oxidation/corrosion resistance for fly ash capture is a key to enabling advanced coal combustion and power generation technologies. Compared to ceramic filters, metallic filters can offer increased resistance to impact and thermal fatigue, greatly improving filter reliability. A beneficial metallic filter structure, composed of a thin-wall (0.5mm) tube with uniform porosity (about 30%), is being developed using a unique spherical powder processing and partial sintering approach, combined with porous sheet rolling and resistance welding. Alloy choices based on modified superalloys, e.g., Ni-16Cr-4.5Al-3Fe (wt.%), are being tested in porous and bulk samples for oxide (typically alumina) scale stability in simulated oxidizing/sulfidizing atmospheres found in PFBC and IGCC systems at temperatures up to 850 C. Recent ''hanging o-ring'' exposure tests in actual combustion systems at a collaborating DOE site (EERC) have been initiated to study the combined corrosive effects from particulate deposits and hot exhaust gases. New studies are exploring the correlation between sintered microstructure, tensile strength, and permeability of porous sheet samples.
Anderson, I.E.; Gleeson, B.; Terpstra, R.L.
An Energy Based Fatigue Life Prediction Framework for In-Service Structural Components
An energy based fatigue life prediction framework has been developed for calculation of remaining fatigue life of in service gas turbine materials. The purpose of the life prediction framework is to account aging effect caused by cyclic loadings on fatigue strength of gas turbine engines structural components which are usually designed for very long life. Previous studies indicate the total strain energy dissipated during a monotonic fracture process and a cyclic process is a material property that can be determined by measuring the area underneath the monotonic true stress-strain curve and the sum of the area within each hysteresis loop in the cyclic process, respectively. The energy-based fatigue life prediction framework consists of the following entities: (1) development of a testing procedure to achieve plastic energy dissipation per life cycle and (2) incorporation of an energy-based fatigue life calculation scheme to determine the remaining fatigue life of in-service gas turbine materials. The accuracy of the remaining fatigue life prediction method was verified by comparison between model approximation and experimental results of Aluminum 6061-T6. The comparison shows promising agreement, thus validating the capability of the framework to produce accurate fatigue life prediction.
H. Ozaltun; M. H.H. Shen; T. George; C. Cross
Structural fatigue assessment and management of large-scale port logistics equipments
With the advances of port enterprises, much intensive research has been gradually involved in the structural fatigue assessment and management of port logistics equipments. However, relevant work on large-scale port logistics equipments is still ... Keywords: S-N curve, crack formation, crack propagation life, fatigue assessment, fracture mechanics, gantry cranes, large-scale port logistics equipment, structural safety assessment
Yuan Liu; Weijian Mi; Huiqiang Zheng
Research on Bolt's Fatigue Characters and Parametric Modeling Based on GL
Base on the ��Guideline for the Certification of Wind Turbines��, this paper describes the problem of bolt fatigue broken and its mechanical behaviors under an alternating load. In order to solve the problem and to find a regulation, various types ... Keywords: Bolt connection, Fatigue, GL, Wind turbine, FEM, Parametric modeling
Jingwei Zhou, Wufu Ma
Fatigue Crack Growth Characteristics of Thin Sheet Titanium Alloy Ti 6-2-2-2-2
Fatigue crack growth rates of Ti 6-2-2-2-2 as a function of stress ratio, temperature (24 or 177 degrees C), tensile orientation and environment (laboratory air or ultrahigh vacuum) are presented. Fatigue crack growth rates of Ti 6-2-2-2-2 are also compared ...
Smith Stephen W.; Piascik Robert S.
FATIGUEPRO(TM) On-Line Fatigue Monitoring System: Demonstration at the Quad Cities BWR
The FATIGUEPRO system can improve nuclear plant reliability and contribute to plant life extension by calculating accumulated fatigue usage for critical components. In cooperation with Commonwealth Edison Company (CECo), EPRI demonstrated the system at the Quad Cities unit 2 BWR to monitor fatigue on-line.
Time-domain Fatigue Response and Reliability Analysis of Offshore Wind Turbines with
-domain based simulation model of 750 kW land-based wind turbine Gear contact fatigue analysis of a wind of 750 kW land-based wind turbine Gear contact fatigue analysis of a wind turbine drive train under response and reliability analysis #12;Time domain based simulation model of 750 kW land-based wind turbine
Nørvåg, Kjetil
Extracting metals directly from metal oxides
A method of extracting metals directly from metal oxides by exposing the oxide to a supercritical fluid solvent containing a chelating agent is described. Preferably, the metal is an actinide or a lanthanide. More preferably, the metal is uranium, thorium or plutonium. The chelating agent forms chelates that are soluble in the supercritical fluid, thereby allowing direct removal of the metal from the metal oxide. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of .beta.-diketones, halogenated .beta.-diketones, phosphinic acids, halogenated phosphinic acids, carboxylic acids, halogenated carboxylic acids, and mixtures thereof. In especially preferred embodiments, at least one of the chelating agents is fluorinated. The method provides an environmentally benign process for removing metals from metal oxides without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the metal recovered, to provide an economic, efficient process.
Wai, Chien M. (Moscow, ID); Smart, Neil G. (Moscow, ID); Phelps, Cindy (Moscow, ID)
A method of extracting metals directly from metal oxides by exposing the oxide to a supercritical fluid solvent containing a chelating agent is described. Preferably, the metal is an actinide or a lanthanide. More preferably, the metal is uranium, thorium or plutonium. The chelating agent forms chelates that are soluble in the supercritical fluid, thereby allowing direct removal of the metal from the metal oxide. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of {beta}-diketones, halogenated {beta}-diketones, phosphinic acids, halogenated phosphinic acids, carboxylic acids, halogenated carboxylic acids, and mixtures thereof. In especially preferred embodiments, at least one of the chelating agents is fluorinated. The method provides an environmentally benign process for removing metals from metal oxides without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the metal recovered, to provide an economic, efficient process. 4 figs.
Wai, C.M.; Smart, N.G.; Phelps, C.
Enhanced fatigue and aging resistance using reactive powders in the optical fiber buffer coating V. V. Rondinella
Enhanced fatigue and aging resistance using reactive powders in the optical fiber buffer coating V causes a dramatic improvement in the fatigue and aging resistance both in aqueous and in constant for the surface roughening that causes the fatigue knee and strength degradation during zero-stress aging
Matthewson, M. John
Effect of seawater environmental exposure on fatigue properties of polyethylene pipe
One laboratory study at NIT was reported to show an unexpected decrease in crystallinity for a polyethylene material exposed to fatigue loading in a synthetic seawater solution. High density polyethylene Sclairpipe, from the OTEC-1 cold water pipe, was evaluated for resistance to corrosion fatigue in natural seawater. Intermediate crystallinity measurements (via bulk density) showed no effect of corrosion fatigue exposure. Heat of fusion (a relative indicator of crystallinity) also showed no effect of the exposure. Seawater exposure produced no significant change in tensile strength. One failure was observed during the corrosion fatigue tests and was attributed to porosity observed by fractography. These data suggest that high density polyethylene is not significantly sensitive to degradation of fatigue strength in natural seawater.
Tipton, D G
Machining of Aircraft Titanium with Abrasive-Waterjets for Fatigue Critical Applications
Laboratory tests were conducted to determine the fatigue performance of AWJ-machined aircraft titanium. Dog-bone specimens machined with AWJs were prepared and tested with and without sanding and dry-grit blasting with Al2O3 as secondary processes. The secondary processes were applied to remove the visual appearance of AWJ-generated striations and to clean up the garnet embedment. The fatigue performance of AWJ-machined specimens was compared with baseline specimens machined with CNC milling. Fatigue test results not only confirmed the findings of the aluminum dog-bone specimens but also further enhance the fatigue performance. In addition, titanium is known to be notoriously difficult to cut with contact tools while AWJs cut it 34% faster than stainless steel. AWJ cutting and dry-grit blasting are shown to be a preferred combination for processing aircraft titanium that is fatigue critical.
Liu, H. T.; Hovanski, Yuri; Dahl, Michael E.
Fatigue of quasi-isotropic composite cylinders under tension-tension loading
A tension fatigue life prediction methodology based on a through-thickness damage accumulation model is used to predict the fatigue failure of composite coupon specimens. Its applicability to thin-walled cylindrical specimens is investigated by comparing the fatigue behavior of composite coupon specimens to that of composite thin-walled cylindrical specimens. AS4/3501-6 graphite-epoxy coupon specimens and thin-walled cylinder specimens with the same layup sequence of (0/+/- 45/90)s were tested under static and fatigue loading conditions. Reasonably good agreement is found between the measured and predicted lives of the coupon specimens. Although the ultimate stresses of coupon and cylindrical specimens are different, it is observed that their fatigue lives at the same percentage of ultimate stress are nearly identical, independent of the coupon edge effect. 23 refs.
Norman, T.L.; Civelek, T.S.; Prucz, J. (West Virginia Univ., Morgantown (United States))
Laboratory tests were conducted to determine the fatigue performance of abrasive-waterjet- (AWJ-) machined aircraft titanium. Dog-bone specimens machined with AWJs were prepared and tested with and without sanding and dry-grit blasting with Al2O3 as secondary processes. The secondary processes were applied to remove the visual appearance of AWJ-generated striations and to clean up the garnet embedment. The fatigue performance of AWJ-machined specimens was compared with baseline specimens machined with CNC milling. Fatigue test results of the titanium specimens not only confirmed our previous findings in aluminum dog-bone specimens but in comparison also further enhanced the fatigue performance of the titanium. In addition, titanium is known to be difficult to cut, particularly for thick parts, however AWJs cut the material 34% faster han stainless steel. AWJ cutting and dry-grit blasting are shown to be a preferred ombination for processing aircraft titanium that is fatigue critical.
Corrosion Fatigue Testing of GMAW and Laser Weld Overlays
This report is an update of EPRI�s ongoing laboratory study on corrosion fatigue cracking of weld overlays, applied to waterwalls of boilers suffering high wastage. At this point the work is not complete. At least one more year of testing is needed to study the effect of all variables affecting circumferential cracking of weld overlays. Thus all conclusions based on the work completed to date should be considered preliminary. Major trends observed to date are that the corrosivity of the environment along...
Transformation Induced Fatigue of Ni-Rich NiTi Shape Memory Alloy Actuators
In this work the transformation induced fatigue of Ni-rich NiTi shape memory alloys (SMAs) was investigated. The aerospace industry is currently considering implementing SMA actuators into new applications. However, before any new applications can be put into production they must first be certified by the FAA. Part of this certification process includes the actuator fatigue life. In this study, as-received and polished at dogbone SMA specimens underwent transformation induced fatigue testing at constant loading. The constant applied loading ranged from 100 MPa to 200 MPa. Specimens were thermally cycled through complete actuation (above Af to below Mf ) by Joule heating and environmental cooling. There were three cooling environments studied: liquid, gaseous nitrogen and vortex cooled air. It was shown that polished specimens had fatigue lives that were two to four times longer than those of as-received specimens. Test environment was also found to have an effect on fatigue life. Liquid cooling was observed to be corrosive, while the gaseous nitrogen and vortex air cooling were observed to be non-corrosive. The two non-corrosive cooling environments performed similarly with specimen fatigue lives that were twice that of specimens fatigue tested in the corrosive cooling environment. Transformation induced fatigue testing of polished specimens in a non-corrosive environment at 200 MPa had an average fatigue life of 14400 actuation cycles; at 150 MPa the average fatigue life was 20800 cycles and at 100 MPa it was 111000 cycles. For all specimens constant actuation from the beginning of testing until failure was observed, without the need for training. Finally, a microstructural study showed that the Ni3Ti precipitates in the material were one of the causes of crack initiation and propagation in the actuators.
Schick, Justin Ryan
Light Metals 2010
Feb 1, 2010 ... Softcover book: Light Metals 2008 Volume 2: Aluminum Reduction. Hardcover book and CD-ROM: Light Metals 2009�...
Bulk Metallic Glasses IX
... of elements to form metallic-glass alloys] have resulted in the required cooling rate ... Bauschinger Effect in Metallic Glass Nanowires under Cyclic Loading.
Metallic Glass II
Aug 8, 2013 ... Application of Metallic Glass for High Performance Si Solar Cell: ... of the metallic glasses during heating is dependent on the thermal stability of�...
Refractory Metals Committee
The Refractory Metals Committee is part of the Structural Materials Division. Our Mission: Includes all technical aspects of the science of refractory metals and�...
Principal Metals Online
Topic Title: WEB RESOURCE: Principal Metals Online Topic Summary: Principal Metals inventory database. Created On: 2/9/2007 5:41 AM, Topic View:.
Bulk Metallic Glasses XI
Jul 15, 2013 ... A Bulk Metallic Glass with Record-breaking Damage Tolerance ... Oxidation on the Surface Characteristics of Zr-based Bulk Metallic Glasses.
Trending: Metal Oxo Bonds
Trending: Metal Oxo Bonds Trending: Metal Oxo Bonds Trending: Metal Oxo Bonds Print Wednesday, 29 May 2013 00:00 Metal oxides are important for scientific and technical applications in a variety of disciplines, including materials science, chemistry, and biology. Highly covalent metal-oxygen multiple bonds (metal oxos) are the building blocks of metal oxides and have a bearing on the oxide's desirable chemical, magnetic, electronic, and thermal properties. The lack of a more sophisticated grasp of bonding in metal oxides constitutes a roadblock to innovation in a wide variety of important emergent technologies, including industrial catalysis, biomimetic transformations, and artificial photosynthesis. To address this problem, a research team from four national laboratories, three Department of Energy synchrotron user facilities, and the University of Washington has applied spectroscopic and computational analyses to a number of metal oxides, quantifying trends in metal oxo bonding for groups of metals across the periodic table.
High-Cycle Fatigue of Single-Crystal Silicon Thin Films
When subjected to alternating stresses, most materials degrade, e.g., suffer premature failure, due to a phenomenon known as fatigue. It is generally accepted that in brittle materials, such as ceramics, fatigue can only take place in toughened solids, i.e., premature fatigue failure would not be expected in materials such as single crystal silicon. The results of this study, however, appear to be at odds with the current understanding of brittle material fatigue. Twelve thin-film ( 20 m thick) single crystal silicon specimens were tested to failure in a controlled air environment (30 0.1 C, 50 2% relative humidity). Damage accumulation and failure of the notched cantilever beams were monitored electrically during the "fatigue life" test. Specimen lives ranged from about 10 s to 48 days, or 1 10 6 to 1 10 11 cycles before failure over stress amplitudes ranging from approximately 4 to 10 GPa. A variety of mechanisms are discussed in light of the fatigue life data and fracture surface evaluation. [642] Index Terms---Fatigue failure, MEMS devices, single-crystal silicon, thin films.
Christopher L. Muhlstein; Stuart B. Brown; Robert O. Ritchie
Application of Abrasive-Waterjets for Machining Fatigue-Critical Aircraft Aluminum Parts
The effects of dry-grid blasting of AWJ-machined dog-bone specimens of aircraft aluminum with aluminum oxide abrasives were investigated in terms of enhancement in fatigue performance and mitigating concerns of abrasive contamination. Results obtained from fatigue tests have indicated that the surface roughness, Ra, of AWJ-induced striations is inversely proportional to the fatigue life. The fatigue life of AWJ-machined and baseline specimens, excluding those processed with dry-grit blasting, decreases with the increase in Ra. Removal of the striations with dry-grit blasting until they disappear visually only reduces Ra from 3.5 to 2.4 ?m and is still higher than that of the conventionally machined edges with Ra = 1.6 ?m. From the surface roughness point of view, the fatigue life of the dry-grit blasted specimens should not have exceeded that of the baseline counterparts. Yet the dry-grit blasting process has extended the fatigue life of the AWJ-machined specimens and the baseline counterparts by more than four and three times, respectively. The extraordinary boost in the fatigue performance is believed to be attributed to the induction of residual compressive stresses by dry-grit blasting. Such a belief was subsequent confirmed quantitatively through measurements of residual compressive stresses. Dry-grid blasting can be carried out efficiently and cost effectively by stacking AWJ-machined parts together. The benefits gained from dry-grit blasting simply outweigh the marginal cost increase.
Liu, H. T.; Hovanski, Yuri; Dahl, Michael E.; Zeng, J.
Effect of cerium and impurities on fatigue and fracture properties of 8090 alloy sheets
The objective of the present study is to examine the effect of a rare earth addition, Ce, and some impurities, Fe, Si, Na and K, on the fatigue and fracture properties of 8090 Al-Li alloy sheet by means of the determinations for the fatigue life (N{sub f}) under a constant stress amplitude, fatigue crack propagation (FCP) rates and plane stress fracture toughness. Impurity Fe and Si in 8090 alloy sheets increase the fatigue crack propagation rates and impair the fracture properties although they could not bring about significant effect on the fatigue life under the test conditions maximum cyclic stress of 280 MPa, load ratio of 0.1 and Fe + Si content of 0.24%. Impurity Na and K in 8090 alloy sheets reduce the fracture properties and fatigue life. When the level stress intensity factor is higher, or {Delta} K>10{sup 1.1} Mpam{sup 1/2} in the test, Na and K markedly increase the fatigue crack propagation rates. Ce addition in 8090 alloy sheets containing a certain amount of Fe and Si impurities could suppress the effects of Na and K impurities on the fracture behavior. Adding about 0.28% Ce in 8090 alloy containing trace Fe and Si impurities improves the crack propagation resistance and plane stress fracture toughness. However, adding Ce from 0.10% to 0.29% is unprofitable to the fatigue life of 8090 alloy containing more impurities. There are more and coarser Ce-containing compound particles in the alloy sheets with high Ce content. These particles could produce a detrimental effect on the fatigue properties.
Meng Liang; Zheng Xiulin [Northwestern Polytechnical Univ., Xi`an (China). Dept. of Materials Science and Engineering
Ceramic to metal seal
Providing a high strength, hermetic ceramic to metal seal by essentially heating a wire-like metal gasket and a ceramic member, which have been chemically cleaned, while simultaneously deforming from about 50 to 95 percent the metal gasket against the ceramic member at a temperature of about 30 to 75 percent of the melting temperature of the metal gasket.
Snow, Gary S. (Albuquerque, NM); Wilcox, Paul D. (Albuquerque, NM)
This patent covers a method and apparatus for collecting the molten metal produced by high temperature metal salt reduction. It consists essentially of subjecting the reaction vessel to centrifugal force in order to force the liberatcd molten metal into a coherent molten mass, and allowing it to solidify there. The apparatus is particularly suitable for use with small quantities of rare metals.
Magel, T.T.
Precious Metals Conversion Information
Precious Metals Conversion Information. The Office of Weights and Measures (OWM) has prepared a Conversion Factors ...
Corrosion of valve metals
A general survey related to the corrosion of valve metals or film-forming metals. The way these metals corrode with some general examples is described. Valve metals form relatively perfect oxide films with little breakdown or leakage when anodized. (FS)
Draley, J.E.
Trending: Metal Oxo Bonds Print Trending: Metal Oxo Bonds Print Metal oxides are important for scientific and technical applications in a variety of disciplines, including materials science, chemistry, and biology. Highly covalent metal-oxygen multiple bonds (metal oxos) are the building blocks of metal oxides and have a bearing on the oxide's desirable chemical, magnetic, electronic, and thermal properties. The lack of a more sophisticated grasp of bonding in metal oxides constitutes a roadblock to innovation in a wide variety of important emergent technologies, including industrial catalysis, biomimetic transformations, and artificial photosynthesis. To address this problem, a research team from four national laboratories, three Department of Energy synchrotron user facilities, and the University of Washington has applied spectroscopic and computational analyses to a number of metal oxides, quantifying trends in metal oxo bonding for groups of metals across the periodic table.
Thermal fatigue behavior of US and Russian grades of beryllium
A novel technique has been used to test the relative low cycle thermal fatigue resistance of different grades of US and Russian beryllium which is proposed as plasma facing armor for fusion reactor first wall, limiter, and divertor components. The 30 KW electron beam test system at Sandia National Laboratories was used to sweep the beam spot along one direction at 1 Hz. This produces a localized temperature ``spike`` of 750{degrees}C for each pass of the beam. Large thermal stress in excess of the yield strength are generated due to very high spot heat flux, 250 MW/m{sup 2}. Cyclic plastic strains on the order of 0.6% produced visible cracking on the heated surface in less than 3000 cycles. An in-vacuo fiber optic borescope was used to visually inspect the beryllium surfaces for crack initiation. Grades of US beryllium tested included: S-65C, S-65H, S-200F, S-300F-H, Sr-200, I-400, extruded high purity. HIP`d sperical powder, porous beryllium (94% and 98% dense), Be/30% BeO, Be/60% BeO, and TiBe{sub 12}. Russian grades included: TGP-56, TShGT, DShG-200, and TShG-56. Both the number of cycles to crack initiation, and the depth of crack propagation, were measured. The most fatigue resistant grades were S-65C, DShG-200, TShGT, and TShG-56. Rolled sheet Be(SR-200) showed excellent crack propagation resistance in the plane of rolling, despite early formation of delamination cracks. Only one sample showed no evidence of surface melting, Extruded (T). Metallographic and chemical analyses are provided. Good agreement was found between the measured depth of cracks and a 2-D elastic-plastic finite element stress analysis.
Watson, R.D.; Youchison, D.L. [Sandia National Labs., Albuquerque, NM (United States); Dombrowski, D.E. [Brush Wellman, Inc., Cleveland, OH (United States); Guiniatouline, R.N. [Efremov Institute, St. Petersburg (USSR); Kupriynov, I.B. [Russian Inst. of Inorganic Materials, Moscow (USSR)
Review of the margins for ASME code fatigue design curve - effects of surface roughness and material variability.
The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. The Code specifies fatigue design curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Existing fatigue strain-vs.-life ({var_epsilon}-N) data illustrate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. This report provides an overview of the existing fatigue {var_epsilon}-N data for carbon and low-alloy steels and wrought and cast austenitic SSs to define the effects of key material, loading, and environmental parameters on the fatigue lives of the steels. Experimental data are presented on the effects of surface roughness on the fatigue life of these steels in air and LWR environments. Statistical models are presented for estimating the fatigue {var_epsilon}-N curves as a function of the material, loading, and environmental parameters. Two methods for incorporating environmental effects into the ASME Code fatigue evaluations are discussed. Data available in the literature have been reviewed to evaluate the conservatism in the existing ASME Code fatigue evaluations. A critical review of the margins for ASME Code fatigue design curves is presented.
Chopra, O. K.; Shack, W. J.; Energy Technology
Toxicology as a nanoscience? � Disciplinary identities reconsidered
This is an Open Access article distributed under the terms of the Creative Commons Attribution License
Fibre Toxicology; Monika Kurath; Sabine Maasen
Bio-inspired Polymers for Nanoscience Research
the kinetics and thermodynamics of folding polymer chains into stable tertiary structures are still not fully understood. Thus, ...
Nanoscience and Technology | Argonne National Laboratory
and future. Argonne Press Releases Microorganisms found in salt flats could offer new path to green hydrogen fuel July 16, 2013 Scientists combine X-rays and microscopes for...
Materials for nuclear energy system, fission reactors, nuclear fuels, energy policy, sustainability and gene therapy. Xudong Wang Assistant Professor, Materials Science & Engineering Nanomaterials growth; nanomaterials for energy storage; nanoelectronics; nano-biomaterials. Jay Samuel Senior Lecturer in Materials
Farritor, Shane
PNNL: Nanoscience and Nanotechnology - Workshops Archive
Sustainable Nanotechnology Organization (SNO) November 4-6, 2012, Washington DC. IEEE NANO - 12th International Conference on Nanotechnology August 20-23, 2012, Birmingham, UK...
PNNL: Nanoscience and Nanotechnology - Website References
Commercialization Education Foundation: 2nd Edition of International Micro-Nano Roadmap NanoMarkets Printable Electronics: Roadmaps, Markets and Opportunities NIH...
Report on Assessment of Environmentally--Assisted Fatigue for LWR Extended
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
on Assessment of Environmentally--Assisted Fatigue for LWR on Assessment of Environmentally--Assisted Fatigue for LWR Extended Service Conditions Report on Assessment of Environmentally--Assisted Fatigue for LWR Extended Service Conditions This report provides an update on the assessment of environmentally-assisted fatigue for light water reactor (LWR) extended service conditions. The report is a deliverable in FY11 under the work package for LWRS under the Advanced Reactor Concepts. Most of the current fleet of aging LWRs were designed using the 1970s version of the ASME Boiler and Pressure Vessels Code, Section III, and are reaching their design lifetime of 30-40 yrs. For economic reasons, the utilities have great interest in extending the operating life of the plants via the Nuclear Regulatory Commission (NRC) licensing renewal application
Materials Reliability Program: Computer-Based NDE Training for Thermal Fatigue Cracking (MRP-36, Revision 2)
This product comes packaged together and contains both #1022875, Materials Reliability Program: NDE Technology for Detection of Thermal Fatigue Damage in Piping, (MRP-23, Revision 1) and Product #1024915, Computer-Based NDE Training for Thermal ...
High cycle fatigue of polycrystalline silicon thin films in laboratory air
When subjected to alternating stresses, most materials degrade, e.g., suffer premature failure, due to a phenomenon known as fatigue. It is generally accepted that in brittle materials, such as ceramics, cyclic fatigue can only take place where there is some degree of toughening, implying that premature fatigue failure would not be expected in polycrystalline silicon where such toughening is absent. However, the fatigue failure of polysilicon is reported in the present work, based on tests on thirteen thin-film (2 �m thick) specimens cycled to failure in laboratory air (~25�C, 30-50 % relative humidity), where damage accumulation and failure of the notched cantilever beams were monitored electrically during the test. Specimen lives ranged from about 10 seconds to 34 days (5 x 10 5 to 1 x 10 11 cycles) with the stress amplitude at failure being reduced to ~50 % of the low-cycle strength for lives in excess of 10 9 cycles.
C. L. Muhlstein; S. B. Brown; R. O. Ritchie
Residual stress relief due to fatigue in tetragonal lead zirconate titanate ceramics
High energy synchrotron XRD was employed to determine the lattice strain {epsilon}{l_brace}111{r_brace}and diffraction peak intensity ratio R{l_brace}200{r_brace}in tetragonal PZT ceramics, both in the virgin poled state and after a bipolar fatigue experiment. It was shown that the occurrence of microstructural damage during fatigue was accompanied by a reduction in the gradient of the {epsilon}{l_brace}111{r_brace}-cos{sup 2} {psi} plot, indicating a reduction in the level of residual stress due to poling. In contrast, the fraction of oriented 90 Degree-Sign ferroelectric domains, quantified in terms of R{l_brace}200{r_brace}, was not affected significantly by fatigue. The change in residual stress due to fatigue is interpreted in terms of a change in the average elastic stiffness of the polycrystalline matrix due to the presence of inter-granular microcracks.
Hall, D. A.; Mori, T. [School of Materials, University of Manchester, Grosvenor St., Manchester M1 7HS (United Kingdom); Comyn, T. P. [Institute for Materials Research, Woodhouse Lane, University of Leeds, LS2 9JT (United Kingdom); Ringgaard, E. [Meggitt Sensing Systems, Hejreskovvej 18A, 3490 Kvistgaard (Denmark); Wright, J. P. [ESRF, 6 Rue Jules Horowitz, BP-220, 38043 Grenoble Cedex (France)
Effect of nano-scale twinning on the fracture, fatigue and wear properties of copper
Grain refinement in materials has been one of the most common strategies for improving the strength of materials. However this comes at the price of reduced ductility, fracture toughness and stable fatigue crack propagation ...
Singh, Aparna, Ph.D. Massachusetts Institute of Technology
Evaluation of Thermal-, Creep-, and Corrosion-Fatigue of Heat Recovery Steam Generator Pressure Parts
The worldwide fleet of combined cycle units with heat recovery steam generators (HRSG) has exhibited a disappointing track record with respect to reliability and availability in terms of fatigue HRSG tube failures (HTF) which are thermal transient driven. This report, which forms part of a series, will assist designer, owners, and operators with the technical basis to facilitate specifying, designing, and operating HRSG in a manner to minimize fatigue damage.
High-cycle fatigue behavior of type 316 stainless steel at 593/sup 0/C
The available low- and high-cycle fatigue data on Type 316 stainless steel at 593 to 600/sup 0/C have been combined and analyzed to provide a preliminary strain-life correlation. This correlation was then reduced by the appropriate safety factors to a design curve and compared with the ASME T-1420-1B curve. The comparison indicates that significant increases in allowable fatigue cycles should be realized when the present study is concluded.
Raske, D.T.
Creep-fatigue of High Temperature Materials for VHTR: Effect of Cyclic Loading and Environment
Alloy 617 is the one of the leading candidate materials for Intermediate Heat eXchangers (IHX) of a Very High Temperature Reactor (VHTR). System start-ups and shut-downs as well as power transients will produce low cycle fatigue (LCF) loadings of components. Furthermore, the anticipated IHX operating temperature, up to 950�C, is in the range of creep so that creep-fatigue interaction, which can significantly increase the fatigue crack growth, may be one of the primary IHX damage modes. To address the needs for Alloy 617 codification and licensing, a significant creep-fatigue testing program is underway at Idaho National Laboratory. Strain controlled LCF tests including hold times up to 1800s at maximum tensile strain were conducted at total strain range of 0.3% and 0.6% in air at 950�C. Creep-fatigue testing was also performed in a simulated VHTR impure helium coolant for selected experimental conditions. The creep-fatigue tests resulted in failure times up to 1000 hrs. Fatigue resistance was significantly decreased when a hold time was added at peak stress and when the total strain was increased. The fracture mode also changed from transgranular to intergranular with introduction of a tensile hold. Changes in the microstructure were methodically characterized. A combined effect of temperature, cyclic and static loading and environment was evidenced in the targeted operating conditions of the IHX. This paper This paper reviews the data previously published by Carroll and co-workers in references 10 and 11 focusing on the role of inelastic strain accumulation and of oxidation in the initiation and propagation of surface fatigue cracks.
Celine Cabet; L. Carroll; R. Wright; R. Madland
Fatigue Crack Propagation in Single Crystal CMSX-2 at Elevated ...
D.L. Anton, T. Khan, R.D. Kissinger, D.L. Klarstrom. The Minerals, Metals & Materials Society, 1992 .... damaged q interface. The SEM stereo pair in Fin. 8 clearly�...
Metal-Air Batteries
Metal-air batteries have much higher specific energies than most currently available primary and rechargeable batteries. Recent advances in electrode materials and electrolytes, as well as new designs on metal-air batteries, have attracted intensive effort in recent years, especially in the development of lithium-air batteries. The general principle in metal-air batteries will be reviewed in this chapter. The materials, preparation methods, and performances of metal-air batteries will be discussed. Two main metal-air batteries, Zn-air and Li-air batteries will be discussed in detail. Other type of metal-air batteries will also be described.
Zhang, Jiguang; Bruce, Peter G.; Zhang, Gregory
Alkali metal nitrate purification
A process is disclosed for removing contaminants from impure alkali metal nitrates containing them. The process comprises heating the impure alkali metal nitrates in solution form or molten form at a temperature and for a time sufficient to effect precipitation of solid impurities and separating the solid impurities from the resulting purified alkali metal nitrates. The resulting purified alkali metal nitrates in solution form may be heated to evaporate water therefrom to produce purified molten alkali metal nitrates suitable for use as a heat transfer medium. If desired, the purified molten form may be granulated and cooled to form discrete solid particles of purified alkali metal nitrates.
Fiorucci, Louis C. (Hamden, CT); Morgan, Michael J. (Guilford, CT)
Effects of Materials Parameters and Design Details on the Fatigue of Composite Materials for Wind Turbine Blades
This paper presents an analysis of the results of nine years of fatigue testing represented in the USDOE/Montana State University (DOE/MSU) Composite Materials Fatigue Database. The focus of the program has been to explore a broad range of glass-fiber-based materials parameters encompassing over 4500 data points for 130 materials systems. Significant trends and transitions in fatigue resistance are shown as the fiber content and fabric architecture are varied. The effects of structural details including ply drops, bonded stiffeners, and other geometries that produce local variations in fiber packing and geometry are also described. Fatigue tests on composite beam structures are then discussed; these show generally good correlation with coupon fatigue data in the database. Goodman diagrams for fatigue design are presented, and their application to predicting the service lifetime of blades is described.
Mandell, J.F.; Samborsky, D.D.; Sutherland, H.J.
Evaluation of Waterwall Corrosion Fatigue, Volume 2: Roadmap Case Study: Evaluation of AEP's Big Sandy Unit 1
As we continue to operate an ever-aging fleet of power plants, we experience increased boiler tube failures from failure mechanisms related to aging. One such failure mechanism is corrosion fatigue. Corrosion fatigue may result in failures in any water-touched surface in boilers and has been found in waterwalls, risers, and supply tubing, and drums. This report provides detailed research on the causes and actions to address corrosion fatigue in boiler waterwall tubing.
Final Report on Round-Robin Conducted in Support of Standard Test Method for Creep-Fatigue Testing
With the increased flexible operation of power plants, many components may now be subject to creep-fatigue damage mechanisms. This report covers the findings from a round-robin test program facilitated by the Electric Power Research Institute (EPRI) with broad international participation. The overall goal was to support the development of a new industry standard for addressing creep-fatigue crack initiation.BackgroundCreep-fatigue is a complex material ...
BWRVIP-196: BWR Vessel and Internals Project, Assessment of Mixing Tee Thermal Fatigue Susceptibility in BWR Plants
In 1998, a French pressurized water reactor (PWR) plant experienced leakage due to thermal fatigue from piping immediately downstream of a residual heat removal (RHR) heat exchanger. EPRI report 1013305, Materials Reliability Program: Assessment of RHR Mixing Tee Thermal Fatigue in PWR Plants (MRP-192), December 2006, was prepared so that owners of PWR plants could determine if their RHR piping systems might be susceptible to similar thermal fatigue cracking and if additional inspection should be recomme...
Metal phthalocyanine catalysts
As a new composition of matter, alkali metal or ammonium or tetraalkylammonium diazidoperfluorophthalocyanatoferrate. Other embodiments of the invention comprise compositions wherein the metal of the coordination complex is cobalt, manganese and chromium.
Ellis, Jr., Paul E. (Downingtown, PA); Lyons, James E. (Wallingford, PA)
A new composition of matter is described which is an alkali metal or ammonium or tetraalkylammonium diazidoperfluorophthalocyanatoferrate. Other embodiments of the invention comprise compositions wherein the metal of the coordination complex is cobalt, manganese and chromium.
Ellis, P.E. Jr.; Lyons, J.E.
Bulk Metallic Glasses X
Jul 31, 2012 ... Aerospace and Spacecraft Applications for Bulk Metallic Glasses and Matrix Composites � Air Oxidation of a Binary Cu64.5Zr35.5 Bulk Metallic�...
Bulk Metallic Glasses VII
Sponsorship, The Minerals, Metals and Materials Society ... Air-Oxidation of a ( Zr55Cu30Al10Ni5)98Er2 Bulk Metallic Glass at 350-500oc � Anelastic�...
Precision metal rulers
... precision metal rulers. Our customers include state bureaus of Weights and Measures and departments of Agriculture. We also ...
Refractory Metals 2011
Aug 2, 2010 ... TMS Structural Materials Division TMS: Refractory Metals Committee. Organizer( s), Omer Dogan, DOE National Energy Technology Laboratory
Fasteners & Metals Program
Directory of Accredited Laboratories. Fasteners & Metals Program. The Fastener Quality Act (FQA), Public Law 101-592, was ...
TMS Light Metals Publication
The following instructions should be used when submitting a manuscript for any TMS Light Metals proceedings volume. INTRODUCTION. Orientation to�...
Goal 4 Long Life Pavement Rehabilitation Strategies-Rigid: Flexural Fatigue Life of Hydraulic Cement Concrete Beams
Flexural Fatigue Life of Hydraulic Cement Concrete Beamsperformance of Fast-Setting Hydraulic Cement Concrete (and Thermal Expansion of Hydraulic Cement Concrete Mixes�,
Kohler, Erwin R.; Ali, Abdikarim; Harvey, John T
Effect of Creep and Oxidation on Reduced Creep-Fatigue life of Ni-based Alloy 617 at 850 C
Low cycle fatigue (LCF) and creep fatigue testing of Ni-based alloy 617 was carried out at 850 C. Compared with its LCF life, the material s creep fatigue life decreases to different extents depending on test conditions. To elucidate the microstructure-fatigue property relationship for alloy 617 and the effect of creep and oxidation on its fatigue life, systematic microstructural investigations were carried out using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electron backscatter diffraction (EBSD). In LCF tests, as the total strain range increased, deformations concentrated near high angle grain boundaries (HAGBs). The strain hold period in the creep fatigue tests introduced additional creep damage to the material, which revealed the detrimental effect of the strain hold time on the material fatigue life in two ways. First, the strain hold time enhanced the localized deformation near HAGBs, resulting in the promotion of intergranular cracking of alloy 617. Second, the strain hold time encouraged grain boundary sliding, which resulted in interior intergranular cracking of the material. Oxidation accelerated the initiation of intergranular cracking in alloy 617. In the crack propagation stage, if oxidation was promoted and the cyclic oxidation damage was greater than the fatigue damage, oxidation-assisted intergranular crack growth resulted in a significant reduction in the material s fatigue life.
Chen, Xiang [ORNL] [ORNL; Yang, Zhiqing [ORNL] [ORNL; Sokolov, Mikhail A [ORNL] [ORNL; ERDMAN III, DONALD L [ORNL] [ORNL; Mo, Kun [ORNL] [ORNL; Stubbins, James [ORNL] [ORNL
A process is described producing metallic thorium, titanium, zirconium, or hafnium from the fluoride. In the process, the fluoride is reduced with alkali or alkaline earth metal and a booster compound (e.g. iodine or a decomposable oxysalt) in a sealed bomb at superatmospheric pressure and a temperature above the melting point of the metal to be produced.
Spedding, F.H.; Wilhelm, H.A.; Keller, W.H.
Durable metallized polymer mirror
A metallized polymer mirror construction is disclosed having improved durability against delamination and tunneling, comprising: an outer layer of polymeric material; a metal oxide layer underlying the outer layer of polymeric material; a silver reflective layer underneath the metal oxide layer; and a layer of adhesive attaching the silver layer to a substrate. 6 figs.
Schissel, P.O.; Kennedy, C.E.; Jorgensen, G.J.; Shinton, Y.D.; Goggin, R.M.
DOE/MSU composite material fatigue database: Test methods, materials, and analysis
This report presents a detailed analysis of the results from fatigue studies of wind turbine blade composite materials carried out at Montana State University (MSU) over the last seven years. It is intended to be used in conjunction with the DOE/MSU composite Materials Fatigue Database. The fatigue testing of composite materials requires the adaptation of standard test methods to the particular composite structure of concern. The stranded fabric E-glass reinforcement used by many blade manufacturers has required the development of several test modifications to obtain valid test data for materials with particular reinforcement details, over the required range of tensile and compressive loadings. Additionally, a novel testing approach to high frequency (100 Hz) testing for high cycle fatigue using minicoupons has been developed and validated. The database for standard coupon tests now includes over 4,100 data points for over 110 materials systems. The report analyzes the database for trends and transitions in static and fatigue behavior with various materials parameters. Parameters explored are reinforcement fabric architecture, fiber content, content of fibers oriented in the load direction, matrix material, and loading parameters (tension, compression, and reversed loading). Significant transitions from good fatigue resistance to poor fatigue resistance are evident in the range of materials currently used in many blades. A preliminary evaluation of knockdowns for selected structural details is also presented. The high frequency database provides a significant set of data for various loading conditions in the longitudinal and transverse directions of unidirectional composites out to 10{sup 8} cycles. The results are expressed in stress and strain based Goodman Diagrams suitable for design. A discussion is provided to guide the user of the database in its application to blade design.
Mandell, J.F.; Samborsky, D.D. [Montana State Univ., Bozeman, MT (United States). Dept. of Chemical Engineering
Silica Embedded Metal Hydrides
A method to produce silica embedded metal hydride was developed. The product is a composite in which metal hydride particles are embedded in a matrix of silica. The silica matrix is highly porous. Hydrogen gas can easily reach the embedded metal hydride particles. The pores are small so that the metal hydride particles cannot leave the matrix. The porous matrix also protects the metal hydride particles from larger and reactive molecules such as oxygen, since the larger gas molecules cannot pass through the small pores easily. Tests show that granules of this composite can absorb hydrogen readily and withstand many cycles without making fines.
Heung, L.K. [Westinghouse Savannah River Company, AIKEN, SC (United States); Wicks, G.G.
Extraction process for removing metallic impurities from alkalide metals
A development is described for removing metallic impurities from alkali metals by employing an extraction process wherein the metallic impurities are extracted from a molten alkali metal into molten lithium metal due to the immiscibility of the alkali metals in lithium and the miscibility of the metallic contaminants or impurities in the lithium. The purified alkali metal may be readily separated from the contaminant-containing lithium metal by simple decanting due to the differences in densities and melting temperatures of the alkali metals as compared to lithium.
Royer, Lamar T. (Knoxville, TN)
Royer, L.T.
Novel Experiments to Characterize Creep-Fatigue Degradation in VHTR Alloys
It is well known in energy systems that the creep lifetime of high temperature alloys is significantly degraded when a cyclic load is superimposed on components operating in the creep regime. A test method has been developed in an attempt to characterize creep-fatigue behavior of alloys at high temperature. The test imposes a hold time during the tensile phase of a fully reversed strain-controlled low cycle fatigue test. Stress relaxation occurs during the strain-controlled hold period. This type of fatigue stress relaxation test tends to emphasize the fatigue portion of the total damage and does not necessarily represent the behavior of a component in-service well. Several different approaches to laboratory testing of creep-fatigue at 950�C have been investigated for Alloy 617, the primary candidate for application in VHTR heat exchangers. The potential for mode switching in a cyclic test from strain control to load control, to allow specimen extension by creep, has been investigated to further emphasize the creep damage. In addition, tests with a lower strain rate during loading have been conducted to examine the influence of creep damage occurring during loading. Very short constant strain hold time tests have also been conducted to examine the influence of the rapid stress relaxation that occurs at the beginning of strain holds.
J. K. Wright; J. A. Simpson; L. J. Carroll; R. N. Wright; T.-L. Sham
An analytical study of rail grinding optimization for rail-head fatigue defect prevention
Over the last two decades, the railroad industry has experienced a significant increase in heavy axle loads acting on railroad rails. In addition, railroad operations have been consolidated resulting in the elimination of redundant routes and increased train traffic on the remaining routes. These changes in railroad industry practice have caused an increase in the rate of occurrence of rail head fatigue defects, one potential cause of train derailment. The primary form of maintenance employed by the individual railroads to combat the formation of fatigue defects is rail grinding. Current rail grinding practices involve removal of surface defects and reshaping worn rail, but they do not involve grinding as a means to mitigate internal fatigue damage. In this study, a model for optimizing a grinding schedule which will prevent the formation of internal fatigue defects is proposed. The model includes a statistical representation of wheel loads, a rail head stress analysis, a rail head fatigue analysis, and optimization of a grinding schedule via mathematical programming. Results from using this model indicate that rail grinding might be performed in such a way as to double the useful service life of railroad rail.
Jones, Scott Laurence
Application of measured loads to wind turbine fatigue and reliability analysis
Cyclic loadings produce progressive damage that can ultimately result in wind turbine structural failure. There are many issues that must be dealt with in turning load measurements into estimates of component fatigue life. This paper deals with how the measured loads can be analyzed and processed to meet the needs of both fatigue life calculations and reliability estimates. It is recommended that moments of the distribution of rainflow-range load amplitudes be calculated and used to characterize the fatigue loading. These moments reflect successively more detailed physical characteristics of the loading (mean, spread, tail behavior). Moments can be calculated from data samples and functional forms can be fitted to wind conditions, such as wind speed and turbulence intensity, with standard recession techniques. Distributions of load amplitudes that accurately reflect the damaging potential of the loadings can be estimated from the moments at any, wind condition of interest. Fatigue life can then be calculated from the estimated load distributions, and the overall, long-term, or design spectrum can be generated for any particular wind-speed distribution. Characterizing the uncertainty in the distribution of cyclic loads is facilitated by using a small set of descriptive statistics for which uncertainties can be estimated. The effects of loading parameter uncertainty can then be transferred to the fatigue life estimate and compared with other uncertainties, such as material durability.
Veers, P.S. [Sandia National Labs., Albuquerque, NM (United States); Winterstein, S.R. [Stanford Univ., CA (United States)
Sumitomo Metal Industries Ltd Sumitomo Metals | Open Energy Information
Open Energy Info (EERE)
Sumitomo Metal Industries Ltd Sumitomo Metals Sumitomo Metal Industries Ltd Sumitomo Metals Jump to: navigation, search Name Sumitomo Metal Industries Ltd (Sumitomo Metals) Place Osaka-shi, Osaka, Japan Zip 540-0041 Sector Solar Product Engaged in the steel, engineering, and electronics businesses; works on fuel cell component technology and manufactures silicon wafers for the solar sector. References Sumitomo Metal Industries Ltd (Sumitomo Metals)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Sumitomo Metal Industries Ltd (Sumitomo Metals) is a company located in Osaka-shi, Osaka, Japan . References ↑ "Sumitomo Metal Industries Ltd (Sumitomo Metals)" Retrieved from "http://en.openei.org/w/index.php?title=Sumitomo_Metal_Industries_Ltd_Sumitomo_Metals&oldid=351744"
Atomistic modeling of nanowires, small-scale fatigue damage in cast magnesium, and materials for MEMS.
Lightweight and miniaturized weapon systems are driving the use of new materials in design such as microscale materials and ultra low-density metallic materials. Reliable design of future weapon components and systems demands a thorough understanding of the deformation modes in these materials that comprise the components and a robust methodology to predict their performance during service or storage. Traditional continuum models of material deformation and failure are not easily extended to these new materials unless microstructural characteristics are included in the formulation. For example, in LIGA Ni and Al-Si thin films, the physical size is on the order of microns, a scale approaching key microstructural features. For a new potential structural material, cast Mg offers a high stiffness-to-weight ratio, but the microstructural heterogeneity at various scales requires a structure-property continuum model. Processes occurring at the nanoscale and microscale develop certain structures that drive material behavior. The objective of the work presented in this report was to understand material characteristics in relation to mechanical properties at the nanoscale and microscale in these promising new material systems. Research was conducted primarily at the University of Colorado at Boulder to employ tightly coupled experimentation and simulation to study damage at various material size scales under monotonic and cyclic loading conditions. Experimental characterization of nano/micro damage will be accomplished by novel techniques such as in-situ environmental scanning electron microscopy (ESEM), 1 MeV transmission electron microscopy (TEM), and atomic force microscopy (AFM). New simulations to support experimental efforts will include modified embedded atom method (MEAM) atomistic simulations at the nanoscale and single crystal micromechanical finite element simulations. This report summarizes the major research and development accomplishments for the LDRD project titled 'Atomistic Modeling of Nanowires, Small-scale Fatigue Damage in Cast Magnesium, and Materials for MEMS'. This project supported a strategic partnership between Sandia National Laboratories and the University of Colorado at Boulder by providing funding for the lead author, Ken Gall, and his students, while he was a member of the University of Colorado faculty.
Dunn, Martin L. (University of Colorado, Boulder, CO); Talmage, Mellisa J. (University of Colorado, Boulder, CO); McDowell, David L., 1956- (,-Georgia Institute of Technology, Atlanta, GA); West, Neil (University of Colorado, Boulder, CO); Gullett, Philip Michael (Mississippi State University , MS); Miller, David C. (University of Colorado, Boulder, CO); Spark, Kevin (University of Colorado, Boulder, CO); Diao, Jiankuai (University of Colorado, Boulder, CO); Horstemeyer, Mark F. (Mississippi State University , MS); Zimmerman, Jonathan A.; Gall, K (Georgia Institute of Technology, Atlanta, GA)
Methods are described of inhibiting the corrosion of ferrous metal by contact with heavy liquid metals such as bismuth and gallium at temperatures above 500 icient laborato C generally by bringing nltrogen and either the metal zirconium, hafnium, or titanium into reactlve contact with the ferrous metal to form a thin adherent layer of the nitride of the metal and thereafter maintaining a fractional percentage of the metal absorbed in the heavy liquid metal in contact with the ferrous metal container. The general purpose for uslng such high boiling liquid metals in ferrous contalners would be as heat transfer agents in liquid-metal-fueled nuclear reactors.
Gurinsky, D.H.; Kammerer, O.F.; Sadofsky, J.; Weeks, J.R.
Mechanical fatigue analysis of gold microbeams for RF-MEMS applications by pull-in voltage monitoring
This work is focused on the reliability of gold microcantilevers under the effect of mechanical fatigue. A dedicated device for testing the material is designed and built; the material degradation is monitored during the tests by means of a novel technique ... Keywords: Failure analysis, Fatigue, Gold, MEMS, Reliability
G. Pasquale; A. Som�; A. Ballestra
An implicit integration procedure for an elasto-viscoplastic model and its application to thermomechanical fatigue design of automotive parts
Thermomechanical fatigue (TMF) design has nowadays become essential for many industrial parts and cyclic elasto-viscoplastic constitutive models and their numerical integration are the crucial point of the problem. The paper first presents an implicit ... Keywords: Constitutive model, FEM analysis, Numerical integration, Return mapping, Thermomechanical fatigue, Viscoplasticity
F. Szmytka; M. H. Maitournam; L. R�My
Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loading: Preprint
Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5 MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.
Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.
Estimation of fatigue and extreme load distributions from limited data with application to wind energy systems.
An estimate of the distribution of fatigue ranges or extreme loads for wind turbines may be obtained by separating the problem into two uncoupled parts, (1) a turbine specific portion, independent of the site and (2) a site-specific description of environmental variables. We consider contextually appropriate probability models to describe the turbine specific response for extreme loads or fatigue. The site-specific portion is described by a joint probability distribution of a vector of environmental variables, which characterize the wind process at the hub-height of the wind turbine. Several approaches are considered for combining the two portions to obtain an estimate of the extreme load, e.g., 50-year loads or fatigue damage. We assess the efficacy of these models to obtain accurate estimates, including various levels of epistemic uncertainty, of the turbine response.
Fitzwater, LeRoy M. (Stanford University, Stanford, CA)
Fatigue resistance and microstructure of experimental dual phase Fe/2Si/0. 1C steel
The fatigue behavior of an experimental dual phase Fe/2Si/0.1C steel has been examined as a function of constituent morphology with the objective of developing ferritic-martensitic microstructures with optimum strength and fatigue crack propagation resistance. Microstructure containing fine globular or coarse martensite within a coarse-grained ferritic matrix were found to show the highest fatigue threshold stress intensity range ..delta..K/sub o/ values reported to date (to our knowledge) and certainly the highest combination of strength and ..delta..K/sub o/ for steels (..delta..K/sub o/ values above 19 MPa..sqrt..m with yield strengths in excess of 600 MPa). Such unusually high crack growth resistance is attributed primarily to a meandering crack path morphology which promotes slower crack extension rates from crack deflection and roughness-induced crack closure mechanisms.
Dutta, V.B.; Suresh, S.; Thomas, G.; Ritchie, R.O.
A simple method of estimating wind turbine blade fatigue at potential wind turbine sites
This paper presents a technique of estimating blade fatigue damage at potential wind turbine sites. The cornerstone of this technique is a simple model for the blade`s root flap bending moment. The model requires as input a simple set of wind measurements which may be obtained as part of a routine site characterization study. By using the model to simulate a time series of the root flap bending moment, fatigue damage rates may be estimated. The technique is evaluated by comparing these estimates with damage estimates derived from actual bending moment data; the agreement between the two is quite good. The simple connection between wind measurements and fatigue provided by the model now allows one to readily discriminate between damaging and more benign wind environments.
Barnard, J.C.; Wendell, L.L.
Thermal fatigue due to beam interruptions in a Lead-Bismuth cooled ATW blanket
Thermal fatigue consequences of frequent accelerator beam interruptions are quantified for both sodium and lead-bismuth cooled blankets in current designs for accelerator transmutation of waste devices. Temperature response was calculated using the SASSYS-1 systems analysis code for an immediate drop in beam current from full power to zero. Coolant temperatures from SASSYS-1 were fed into a multi-node structure temperature calculation to obtain thermal strains for various structural components. Fatigue curves from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code were used to determine the number of cycles that these components could endure, based on these thermal strains. Beam interruption frequency data from a current accelerator were used to estimate design lifetimes for components. Mitigation options for reducing thermal fatigue are discussed.
Dunn, F.
A Review of Stress Corrosion Cracking/Fatigue Modeling for Light Water
A Review of Stress Corrosion Cracking/Fatigue Modeling for Light A Review of Stress Corrosion Cracking/Fatigue Modeling for Light Water Reactor Cooling System Components A Review of Stress Corrosion Cracking/Fatigue Modeling for Light Water Reactor Cooling System Components In the United States currently there are approximately 104 operating light water reactors. Of these, 69 are pressurized water reactors (PWRs) and 35 are boiling water reactors (BWRs). In 2007, the 104 light-water reactors (LWRs) in the United States generated approximately 100 GWe, equivalent to 20% of total US electricity production. Most of the US reactors were built before 1970 and the initial design lives of most of the reactors are 40 years. It is expected that by 2030, even those reactors that have received 20-year life extension license from the US Nuclear Regulatory Commission
Supported metal alloy catalysts
A process of preparing a Group IV, V, or VI metal carbonitride including reacting a Group IV, V, or VI metal amide complex with ammonia to obtain an intermediate product; and, heating the intermediate product to temperatures and for times sufficient to form a Group IV, V, or VI metal carbonitride is provided together with the product of the process and a process of reforming an n-alkane by use of the product.
Barrera, Joseph (Albuquerque, NM); Smith, David C. (Santa Clara, CA)
Metal atomization spray nozzle
A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal.
Huxford, Theodore J. (Harriman, TN)
A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.
Huxford, T.J.
Metal atom oxidation laser
A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides. (auth)
Jensen, R.J.; Rice, W.W.; Beattie, W.H.
A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides.
Characterization of Light Metals
Mar 15, 2012 ... Characterization of Grit Blasted Metallic Biomaterials by ... The grit blasting, a surface improvement treatment is used to enhance mechanical�...
Metal Matrix Composites - TMS
METAL- MATRIX COMPOSITES UNDER MULTI- AXIAL LOADINGS: M. V. S. Ravisankar ... including the values of the stress exponent and the activation energy.
The advantages and disadvantages of the electron welding of metals are briefly reviewed. Typical apparatuses used for electron welding are described. (J.S.R)
Stohr, J.-A.
The Effect of Tube Bend Geometry on the Development of Corrosion Fatigue Damage
Corrosion fatigue cracking in supply and riser tubing has occurred in a range of fossil plants. Tubing of this type can run outside the boiler so that, in some cases, the failures result in significant damage and risk for the safety of personnel. The overall EPRI effort in examining corrosion fatigue damage in supply and riser tube systems is aimed at the following: Developing a set of case studies in which the background is collated on plants exhibiting problems as well as plants where no significant da...
Fatigue analysis of WECS (Wind Energy Conversion System) components using a rainflow counting algorithm
A rainflow counting algorithm'' has been incorporated into the LIFE2 fatigue/fracture analysis code for wind turbines. The count algorithm, with its associated pre- and post-count algorithms, permits the code to incorporate time-series data into its analysis scheme. After a description of the algorithms used here, their use is illustrated by the examination of stress-time histories from the Sandia 34-m Test Bed vertical axis wind turbine. The results of the rainflow analysis are compared and contrasted to previously reported predictions for the service lifetime of the fatigue critical component for this turbine. 14 refs., 8 figs., 3 tabs.
Sutherland, H.J.; Schluter, L.L.
Simulation and Experiment of Thermal Fatigue in the CPV Die Attach: Preprint
FEM simulation and accelerated thermal cycling have been performed for the CPV die attach. Trends in fatigue damage accumulation and equivalent test time are explored and found to be most sensitive to temperature ramp rate. Die attach crack growth is measured through cycling and found to be in excellent agreement with simulations of the inelastic strain energy accumulated. Simulations of an entire year of weather data provides for the relative ranking of fatigue damage between four cites as well as their equivalent accelerated test time.
Bosco, N.; Silverman, T.; Kurtz, S.
Sensitivity of Solder Joint Fatigue to Sources of Variation in Advanced Vehicular Power Electronics Cooling
This paper demonstrates a methodology for taking variation into account in thermal and fatigue analyses of the die attach for an inverter of an electric traction drive vehicle. This method can be used to understand how variation and mission profile affect parameters of interest in a design. Three parameters are varied to represent manufacturing, material, and loading variation: solder joint voiding, aluminum nitride substrate thermal conductivity, and heat generation at the integrated gate bipolar transistor. The influence of these parameters on temperature and solder fatigue life is presented. The heat generation loading variation shows the largest influence on the results for the assumptions used in this problem setup.
Vlahinos, A.; O' Keefe, M.
One-Year Longitudinal Study of Fatigue, Cognitive Functions, and Quality of Life After Adjuvant Radiotherapy for Breast Cancer
Purpose: Most patients with localized breast cancer (LBC) who take adjuvant chemotherapy (CT) complain of fatigue and a decrease in quality of life during or after radiotherapy (RT). The aim of this longitudinal study was to compare the impact of RT alone with that occurring after previous CT on quality of life. Methods and Materials: Fatigue (the main endpoint) and cognitive impairment were assessed in 161 CT-RT and 141 RT patients during RT and 1 year later. Fatigue was assessed with Functional Assessment of Cancer Therapy-General questionnaires, including breast and fatigue modules. Results: At baseline, 60% of the CT-RT patients expressed fatigue vs. 33% of the RT patients (p <0.001). Corresponding values at the end of RT were statistically similar (61% and 53%), and fatigue was still reported at 1 year by more than 40% of patients in both groups. Risk factors for long-term fatigue included depression (odds ratio [OR] = 6), which was less frequent in the RT group at baseline (16% vs. 28 %, respectively, p = 0.01) but reached a similar value at the end of RT (25% in both groups). Initial mild cognitive impairments were reported by RT (34 %) patients and CT-RT (24 %) patients and were persistent at 1 year for half of them. No biological disorders were associated with fatigue or cognitive impairment. Conclusions: Fatigue was the main symptom in LBC patients treated with RT, whether they received CT previously or not. The correlation of persistent fatigue with initial depressive status favors administering medical and psychological programs for LBC patients treated with CT and/or RT, to identify and manage this main quality-of-life-related symptom.
Noal, Sabine [Medical Oncology Department, Centre Francois Baclesse, Caen (France); Clinical Research Department, Centre Francois Baclesse, Caen (France); Levy, Christelle [Medical Oncology Department, Centre Francois Baclesse, Caen (France); Hardouin, Agnes [Department of Medical Biology, Centre Francois Baclesse, Caen (France); Rieux, Chantal [Clinical Research Department, Centre Francois Baclesse, Caen (France); Heutte, Natacha [Universite de Caen Basse Normandie GRECAN, Caen (France); Segura, Carine [Medical Oncology Department, Centre Francois Baclesse, Caen (France); Collet, Fabienne [Clinical Research Department, Centre Francois Baclesse, Caen (France); Allouache, Djelila; Switsers, Odile; Delcambre, Corinne; Delozier, Thierry [Medical Oncology Department, Centre Francois Baclesse, Caen (France); Henry-Amar, Michel [Clinical Research Department, Centre Francois Baclesse, Caen (France); Joly, Florence, E-mail: email@example.com [Medical Oncology Department, Centre Francois Baclesse, Caen (France); Clinical Research Department, Centre Francois Baclesse, Caen (France); CHU, Cote de Nacre, Caen (France)
Spectrum Fatigue Lifetime and Residual Strength for Fiberglass Laminates
This report addresses the effects of spectrum loading on lifetime and residual strength of a typical fiberglass laminate configuration used in wind turbine blade construction. Over 1100 tests have been run on laboratory specimens under a variety of load sequences. Repeated block loading at two or more load levels, either tensile-tensile, compressive-compressive, or reversing, as well as more random standard spectra have been studied. Data have been obtained for residual strength at various stages of the lifetime. Several lifetime prediction theories have been applied to the results. The repeated block loading data show lifetimes that are usually shorter than predicted by the most widely used linear damage accumulation theory, Miner's sum. Actual lifetimes are in the range of 10 to 20 percent of predicted lifetime in many cases. Linear and nonlinear residual strength models tend to fit the data better than Miner's sum, with the nonlinear providing a better fit of the two. Direct tests of residual strength at various fractions of the lifetime are consistent with the residual strength models. Load sequencing effects are found to be insignificant. The more a spectrum deviates from constant amplitude, the more sensitive predictions are to the damage law used. The nonlinear model provided improved correlation with test data for a modified standard wind turbine spectrum. When a single, relatively high load cycle was removed, all models provided similar, though somewhat non-conservative correlation with the experimental results. Predictions for the full spectrum, including tensile and compressive loads were slightly non-conservative relative to the experimental data, and accurately captured the trend with varying maximum load. The nonlinear residual strength based prediction with a power law S-N curve extrapolation provided the best fit to the data in most cases. The selection of the constant amplitude fatigue regression model becomes important at the lower stress, higher cycle loading cases. The residual strength models may provide a more accurate estimate of blade lifetime than Miner's rule for some loads spectra. They have the added advantage of providing an estimate of current blade strength throughout the service life.
Clean Metal Spray Forming
controlled transfer of liquid metal from the ESR pool to the spray forming system is performed using a ... heating to maintain superheat and avoid freezing of the liquid metal as it flows through the funnel. ... As is the case with all similar cross-.
Porous metallic bodies
Porous metallic bodies having a substantially uniform pore size of less than about 200 microns and a density of less than about 25 percent theoretical, as well as the method for making them, are disclosed. Group IIA, IIIB, IVB, VB, and rare earth metal hydrides a
Landingham, R.L.
Liquid metal hydrogen barriers
Hydrogen barriers which comprise liquid metals in which the solubility of hydrogen is low and which have good thermal conductivities at operating temperatures of interest. Such barriers are useful in nuclear fuel elements containing a metal hydride moderator which has a substantial hydrogen dissociation pressure at reactor operating temperatures.
Grover, George M. (Los Alamos, NM); Frank, Thurman G. (Los Alamos, NM); Keddy, Edward S. (Los Alamos, NM)
A process is given for producing plutonium metal by the reduction of plutonium chloride, dissolved in alkali metal chloride plus or minus aluminum chloride, with magnesium or a magnesium-aluminum alloy at between 700 and 800 deg C and separating the plutonium or plutonium-aluminum alloy formed from the salt.
Lyon, W.L.; Moore, R.H.
Explosion metal welding
Process parameters pertaining to welding similar and dissimilar metals using explosives are reviewed. The discussion centers on the interrelationship of physical parameters which play a part in achieving desirable metallurgical results. Present activities in explosion metal welding at LASL are presented and shown how they related to the interests of the ERDA community.
Popoff, A.A.
Production of magnesium metal
A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention further relates to a process for production of magnesium metal or a magnesium compound where an external source of carbon dioxide is not used in any of the reactions of the process. The invention also relates to the magnesium metal produced by the processes described herein.
Blencoe, James G. (Harriman, TN); Anovitz, Lawrence M. (Knoxville, TN); Palmer, Donald A. (Oliver Springs, TN); Beard, James S. (Martinsville, VA)
Hold-Time Effects on Low-Cycle-Fatigue Behavior of Hastelloy� X ...
Total strain-controlled low-cycle-fatigue tests with and without hold times were ... frequency-modified tensile-hysteresis-energy method. The predicted lives were ... usage of this material in gas-turbine and chemical-process industries is based�...
A New Method To Predict Fatigue Crack Growth Life for the Armored Hull
Based on theories of dynamics of multi-body systems and linear elastic fracture mechanics, by using virtual prototyping technique, the model of tracked vehicle is established, and stress spectrums of the armored hull�s weak points are tested by ... Keywords: Virtual Prototyping, Virtual Test, Fatigue Crack Grow, Simulation
Wang Hongyan; Yang Tao; Shang Qigang
Understanding Microstructural Effects on Long Term Electrical Fatigue in Multilayer PZT Actuators*
and lower device degradation with usage time was observed. Keywords: lead zirconate titanate, PbTixZr1-xO3Understanding Microstructural Effects on Long Term Electrical Fatigue in Multilayer PZT Actuators to 1325 °C. Sintering times were 6 and 24 minutes. Samples were poled and additionally electrically
Balzar, Davor
Substrate Creep on The Fatigue Life of A Model Dental Multilayer Structure
In this paper, we investigated the effects of substrate creep on the fatigue behavior of a model dental multilayer structure, in which a top glass layer was bonded to a polycarbonate substrate through a dental adhesive. The top glass layers were ground using 120 grit or 600 grit sand papers before bonding to create different sub-surface crack sizes and morphologies. The multilayer structures were tested under cyclic Hertzian contact loading to study crack growth and obtain fatigue life curves. The experiment results showed that the fatigue lives of the multilayer structures were impaired by increasing crack sizes in the sub-surfaces. They were also significantly reduced by the substrate creep when tested at relatively low load levels i.e. P{sub m} < 60 N (Pm is the maximum magnitude of cyclic load). But at relatively high load levels i.e. P{sub m} > 65 N, slow crack growth (SCG) was the major failure mechanisms. A modeling study was then carried out to explore the possible failure mechanisms over a range of load levels. It is found that fatigue life at relatively low load levels can be better estimated by considering the substrate creep effect (SCE).
Zhou, J; Huang, M; Niu, X; soboyejo, W
In this paper, we investigated the effects of substrate creep on the fatigue behavior of a model dental multilayer structure, in which a top glass layer was bonded to a polycarbonate substrate through a dental adhesive. The top glass layers were ground using 120 grit or 600 grit sand papers before bonding to create different sub-surface crack sizes and morphologies. The multilayer structures were tested under cyclic Hertzian contact loading to study crack growth and obtain fatigue life curves. The experiment results showed that the fatigue lives of the multilayer structures were impaired by increasing crack sizes in the sub-surfaces. They were also significantly reduced by the substrate creep when tested at relatively low load levels i.e. P{sub m} 65 N, slow crack growth (SCG) was the major failure mechanisms. A modeling study was then carried out to explore the possible failure mechanisms over a range of load levels. It is found that fatigue life at relatively low load levels can be better estimated by considering the substrate creep effect (SCE).
International Journal of Fatigue 21 (1999) 725731 www.elsevier.com/locate/ijfatigue
performance materials subject to severe operating conditions in the high temperature turbine section of gas fatigue crack propagation behavior of a nickel-base turbine disk alloy S.A. Padula II a , A. Shyam a , R turbine engines. Turbine blades in modern engines are fabricated from Ni-base alloy single crystals which
Ritchie, Robert
Interfacial delamination and fatigue life estimation of 3D solder bumps in flip-chip packages
fracture behaviors under thermal load. The 3D analysis also estimated thermal fatigue life of solder bumps, small profiles, and good electrical performance, area-array solder-bumped flip-chip technology-dimensional finite element analysis was carried out for area-array solder-bumped flip-chip packages. The analysis
Nakamura, Toshio
Graphene coating makes carbon nanotube aerogels superelastic and resistant to fatigue
Graphene coating makes carbon nanotube aerogels superelastic and resistant to fatigue Kyu Hun Kim-based foams1014 and aero- gels15,16 . However, all nanotube-based foams and aerogels devel- oped so far10,11,13,14 when they are subjected to cyclic strain. Here, we show that an inelastic aerogel made
Islam, Mohammad F.
Influence of Hold Time on Creep-Fatigue Behavior of an Advanced Austenitic Alloy
An advanced austenitic alloy, HT-UPS (high temperature-ultrafine precipitate strengthened), is a candidate material for the structural components of fast reactors and energy-conversion systems. HT-UPS provides improved creep resistance through a composition based on 316 stainless steel (SS) with additions of Ti and Nb to form nano-scale MC precipitates in the austenitic matrix. The low cycle fatigue and creep-fatigue behavior of a HT-UPS alloy has been investigated at 650 C, 1.0% total strain, and an R ratio of -1 with hold times as long as 9000 sec at peak tensile strain. The cyclic deformation response of HT-UPS is compared to that of 316 SS. The cycles to failure are similar, despite differences in peak stress profiles and the deformed microstructures. Cracking in both alloys is transgranular (initiation and propagation) in the case of continuous cycle fatigue, while the primary cracks also propagate transgranularly during creep-fatigue cycling. Internal grain boundary damage as a result of the tensile hold is present in the form of fine cracks for hold times of 3600 sec and longer and substantially more internal cracks are visible in 316 SS than HT-UPS. The dislocation substructures observed in the deformed material are different. An equiaxed cellular structure is observed in 316 SS, whereas tangles of dislocations are present at the nanoscale MC precipitates in HT-UPS and no cellular substructure is observed.
Mark Carroll; Laura Carroll
Delamination of a sensitized commercial AlMg alloy during fatigue crack growth
as sensitization to corrosion and stress corrosion cracking [1,3,4,8], with exposure to tem- peratures between 50,912]. The presence and growth of b-phase have been shown to severely degrade the corrosion resistance and stressDelamination of a sensitized commercial AlMg alloy during fatigue crack growth J.K. Brosi and J
Rollins, Andrew M.
Fatigue of Composite Material Beam Elements Representative of Wind Turbine Blade Substructure
The database and analysis methods used to predict wind turbine blade structural performance for stiffness, static strength, dynamic response,and fatigue lifetime are validated through the design, fabrication, and testing of substructural elements. We chose a test specimen representative of wind turbine blade primary substructure to represent the spar area of a typical wind turbine blade. We then designed an I-beam with flanges and web to represent blade structure, using materials typical of many U.S.-manufactured blades. Our study included the fabrication and fatigue testing of 52 beams and many coupons of beam material. Fatigue lifetimes were consistent with predictions based on the coupon database. The final beam specimen proved to be a very useful tool for validating strength and lifetime predictions for a variety of flange and web materials, and is serving as a test bed to ongoing studies of structural details and the interaction between manufacturing and structural performance. Th e beam test results provide a significant validation of the coupon database and the methodologies for predicting fatigue of composite material beam elements.
Mandell, J. F.; Samborsky, D. D.; Combs, D. W.; Scott, M. E.; Cairns, D. S. (Department of Chemical Engineering, Montana State University)
Fatigue Crack Initiation in Nickel-Based Superalloy Ren� 88 DT at ...
9% distilled water and 13% butyl cellosolve under conditions of. -35�C, 20V and ... The ultrasonic fatigue stress-life curve for Ren� 88 DT at 593?C is shown in Figure 4 ... 600MPa. Figure 4. S-N data of Rene 88 DT at 593?C (Arrows indicate.
2009 ASME WIND ENERGY SYMPOSIUM Static and Fatigue Testing of Thick Adhesive Joints for
1 2009 ASME WIND ENERGY SYMPOSIUM Static and Fatigue Testing of Thick Adhesive Joints for Wind as wind blade size has increased. Typical blade joints use paste adhesives several millimeters thick aircraft, which are also of relevance to wind blades in many instances. The strengths of lap-shear and many
Analysis of SNL/MSU/DOE fatigue database trends for wind turbine blade materials.
This report presents an analysis of trends in fatigue results from the Montana State University program on the fatigue of composite materials for wind turbine blades for the period 2005-2009. Test data can be found in the SNL/MSU/DOE Fatigue of Composite Materials Database which is updated annually. This is the fifth report in this series, which summarizes progress of the overall program since its inception in 1989. The primary thrust of this program has been research and testing of a broad range of structural laminate materials of interest to blade structures. The report is focused on current types of infused and prepreg blade materials, either processed in-house or by industry partners. Trends in static and fatigue performance are analyzed for a range of materials, geometries and loading conditions. Materials include: sixteen resins of three general types, five epoxy based paste adhesives, fifteen reinforcing fabrics including three fiber types, three prepregs, many laminate lay-ups and process variations. Significant differences in static and fatigue performance and delamination resistance are quantified for particular materials and process conditions. When blades do fail, the likely cause is fatigue in the structural detail areas or at major flaws. The program is focused strongly on these issues in addition to standard laminates. Structural detail tests allow evaluation of various blade materials options in the context of more realistic representations of blade structure than do the standard test methods. Types of structural details addressed in this report include ply drops used in thickness tapering, and adhesive joints, each tested over a range of fatigue loading conditions. Ply drop studies were in two areas: (1) a combined experimental and finite element study of basic ply drop delamination parameters for glass and carbon prepreg laminates, and (2) the development of a complex structured resin-infused coupon including ply drops, for comparison studies of various resins, fabrics and pry drop thicknesses. Adhesive joint tests using typical blade adhesives included both generic testing of materials parameters using a notched-lap-shear test geometry developed in this study, and also a series of simulated blade web joint geometries fabricated by an industry partner.
Mandell, John F. (Montana State University, Bozeman, MT); Ashwill, Thomas D.; Wilson, Timothy J. (Montana State University, Bozeman, MT); Sears, Aaron T. (Montana State University, Bozeman, MT); Agastra, Pancasatya (Montana State University, Bozeman, MT); Laird, Daniel L.; Samborsky, Daniel D. (Montana State University, Bozeman, MT)
Fatigue and Creep Crack Propagation behaviour of Alloy 617 in the Annealed and Aged Conditions
The crack propagation behaviour of Alloy 617 was studied under various conditions. Elevated temperature fatigue and creep-fatigue crack growth experiments were conducted at 650 and 800 degrees C under constant stress intensity (triangle K) conditions and triangular or trapezoidal waveforms at various frequencies on as-received, aged, and carburized material. Environmental conditions included both laboratory air and characteristic VHTR impure helium. As-received Alloy 617 displayed an increase in the crack growth rate (da/dN) as the frequency was decreased in air which indicated a time-dependent contribution component in fatigue crack propagation. Material aged at 650�C did not display any influence on the fatigue crack growth rates nor the increasing trend of crack growth rate with decreasing frequency even though significant microstructural evolution, including y� (Ni3Al) after short times, occurred during aging. In contrast, carburized Alloy 617 showed an increase in crack growth rates at all frequencies tested compared to the material in the standard annealed condition. Crack growth studies under quasi-constant K (i.e. creep) conditions were also completed at 650 degrees C and a stress intensity of K = 40 MPa9 (square root)m. The results indicate that crack growth is primarily intergranular and increased creep crack growth rates exist in the impure helium environment when compared to the results in laboratory air. Furthermore, the propagation rates (da/dt) continually increased for the duration of the creep crack growth either due to material aging or evolution of a crack tip creep zone. Finally, fatigue crack propagation tests at 800 degrees C on annealed Alloy 617 indicated that crack propagation rates were higher in air than impure helium at the largest frequencies and lowest stress intensities. The rates in helium, however, eventually surpass the rates in air as the frequency is reduced and the stress intensity is decreased which was not observed at 650 degrees C.
Julian K. Benz; Richard N. Wright
Business Center for Precious Metals
Department of Energy Business Center for Precious Metals Department of Energy Business Center for Precious Metals Becky Eddy National Nuclear Security Administration Y-12 Site...
Nonferrous Metals Society of China
The Nonferrous Metals Society of China (NFSoc) is a technological organization of scientists and technologists engaged in the nonferrous metals industry.
Metal RIE 1: Unaxis 790
... Scientific Opportunities / Applications: Physical milling of most metals; Anisotropic etching of metal films; Anisotropic etching of SiO 2 and SiN x. ...
Static and Fatigue Strength of Dissimilar Al/Steel Spot Welds by ...
Analysis of the Fusion Boundary Region in Dissimilar Metal Welds at Low Dilution � Application of Cold Metal Transfer Process for Structural Weld Overlays and�...
Charged Metallic Clusters
Usually in Nuclear Physics the minimum of the liquid drop model (LDM) energy occurs at a mass asymmetry which is different from the minimum of shell correction. Charged metallic clusters are ideal emitters of singly ionized trimers because both LDM and shell correction are reaching a minimum for the same mass asymmetry corresponding to the emission of a charged particle with two delocalized electrons. Maximum dissociation energy (Q-value) is obtained for metallic clusters with high surface tension and low Wigner-Seitz radius (transition metals). The Q-values for spheroidal shapes are much larger than for hemispheroids.
Poenaru, D. N.; Gherghescu, R. A. [Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), Bucharest-Magurele (Romania); Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Frankfurt am Main (Germany); Solov'yov, A. V.; Greiner, W. [Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Frankfurt am Main (Germany)
Liquid metal electric pump
An electrical pump for pumping liquid metals to high pressures in high temperature environments without the use of magnets or moving mechanical parts. The pump employs a non-porous solid electrolyte membrane, typically ceramic, specific to the liquid metal to be pumped. A DC voltage is applied across the thickness of the membrane causing ions to form and enter the membrane on the electrically positive surface, with the ions being neutralized on the opposite surface. This action provides pumping of the liquid metal from one side of the non-porous solid electrolyte membrane to the other. 3 figs.
Abbin, J.P.; Andraka, C.E.; Lukens, L.L.; Moreno, J.B.
Actinide metal processing
A process for converting an actinide metal such as thorium, uranium, or plutonium to an actinide oxide material by admixing the actinide metal in an aqueous medium with a hypochlorite as an oxidizing agent for sufficient time to form the actinide oxide material and recovering the actinide oxide material is described together with a low temperature process for preparing an actinide oxide nitrate such as uranyl nitrate. Additionally, a composition of matter comprising the reaction product of uranium metal and sodium hypochlorite is provided, the reaction product being an essentially insoluble uranium oxide material suitable for disposal or long term storage.
Sauer, N.N.; Watkin, J.G.
This invention is comprised of a process of converting an actinide metal such as thorium, uranium, or plutonium to an actinide oxide material by admixing the actinide metal in an aqueous medium with a hypochlorite as an oxidizing agent for sufficient time to form the actinide oxide material and recovering the actinide oxide material is provided together with a low temperature process of preparing an actinide oxide nitrate such as uranyl nitrate. Additionally, a composition of matter comprising the reaction product of uranium metal and sodium hypochlorite is provided, the reaction product being an essentially insoluble uranium oxide material suitable for disposal or long term storage.
Influence of process parameters on rolling-contact-fatigue life of ion plated nickel-copper-silver lubrication
In this paper, we present a connection between argon ion flux, element-mixing, and rolling contact fatigue (RCF) life of a thin film nickel-copper-silver lubricant on ball bearings. The film is deposited on the balls using an ion plating process and tested for RCF in high vacuum. The ion flux is measured using a Langmuir probe and the plane stress within the film during deposition is calculated using a thin film model. Experiments reveal that there is an inverse relationship between ion flux and RCF life for most deposition voltage and pressure combinations tested, specifically, 15.5-18.5 mTorr and 1.5-3.5 kV. For voltages up to 2.5 kV, RCF life decreases as ion flux increases due to increased compressive stress within the film, reaching as high as 2.6 GPa. For voltages between 2.5 and 3.5 kV, interlayer mixing of nickel and copper with the silver layer reduces RCF life due to contamination, even as ion flux and corresponding film compressive stress are reduced. A Monte Carlo-based simulation tool, SRIM is used to track collision cascades of the argon ions and metal atoms within the coating layers. At process voltages above 2.5 kV we observe elemental mixing of copper and nickel with the silver layer using Auger electron spectroscopy of coated steel and Si{sub 3}N{sub 4} balls. The authors conclude that an ion flux greater than 5.0 x 10{sup 14} cm{sup -2} s{sup -1} leads to reduced RCF life due to high film stress. In addition, process voltages greater than 2.5 kV also reduce RCF life due to contamination and interlayer mixing of nickel and copper within the silver layer.
Danyluk, Mike; Dhingra, Anoop [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211-3029 (United States)
A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention also relates to the magnesium metal produced by the processes described herein.
Divalent metal nanoparticles
Metal nanoparticles hold promise for many scientific and technological applications, such as chemical and biological sensors, vehicles for drug delivery, and subdiffraction limit waveguides. To fabricate such devices, a ...
DeVries, Gretchen Anne
General Light Metals
Mar 3, 2011 ... A detailed literature survey indicates that vacuum sintering is able to produce ... In recent years, there is a high demand for light-weight metals foams. ... Each powder mixture's composition is determined by response surface�...
Metal Matrix Composites II
Oct 29, 2013... of Al-AC8H/Al2O3p Metal Matrix Composites Produced by Stir Casting Route: Anne Zulfia1; Maman Ajiriyanto1; 1University of Indonesia
Controlled Metal Photodeposition
A reliable syntheses of semiconductor-metal heterostructure has been developed to enable application of materials in catalytic, magnetic, and opto-electronic devices, and Iowa State University, The Ames Laboratory's Contractor, is looking for ...
Lithium metal reduction of plutonium oxide to produce plutonium metal
A method is described for the chemical reduction of plutonium oxides to plutonium metal by the use of pure lithium metal. Lithium metal is used to reduce plutonium oxide to alpha plutonium metal (alpha-Pu). The lithium oxide by-product is reclaimed by sublimation and converted to the chloride salt, and after electrolysis, is removed as lithium metal. Zinc may be used as a solvent metal to improve thermodynamics of the reduction reaction at lower temperatures. Lithium metal reduction enables plutonium oxide reduction without the production of huge quantities of CaO--CaCl.sub.2 residues normally produced in conventional direct oxide reduction processes.
Coops, Melvin S. (Livermore, CA)
Molten metal reactors
A molten metal reactor for converting a carbon material and steam into a gas comprising hydrogen, carbon monoxide, and carbon dioxide is disclosed. The reactor includes an interior crucible having a portion contained within an exterior crucible. The interior crucible includes an inlet and an outlet; the outlet leads to the exterior crucible and may comprise a diffuser. The exterior crucible may contain a molten alkaline metal compound. Contained between the exterior crucible and the interior crucible is at least one baffle.
Bingham, Dennis N; Klingler, Kerry M; Turner, Terry D; Wilding, Bruce M
Coarsening of the Sn-Pb Solder Microstructure in Constitutive Model-Based Predictions of Solder Joint Thermal Mechanical Fatigue
Thermal mechanical fatigue (TMF) is an important damage mechanism for solder joints exposed to cyclic temperature environments. Predicting the service reliability of solder joints exposed to such conditions requires two knowledge bases: first, the extent of fatigue damage incurred by the solder microstructure leading up to fatigue crack initiation, must be quantified in both time and space domains. Secondly, fatigue crack initiation and growth must be predicted since this metric determines, explicitly, the loss of solder joint functionality as it pertains to its mechanical fastening as well as electrical continuity roles. This paper will describe recent progress in a research effort to establish a microstructurally-based, constitutive model that predicts TMF deformation to 63Sn-37Pb solder in electronic solder joints up to the crack initiation step. The model is implemented using a finite element setting; therefore, the effects of both global and local thermal expansion mismatch conditions in the joint that would arise from temperature cycling.
Vianco, P.T.; Burchett, S.N.; Neilsen, M.K.; Rejent, J.A.; Frear, D.R.
Thermo-mechanical fatigue of polycrystalline, directionally solidified and single crystal nickel base superalloys repaired by laser beam welding.
??The low cycle thermo-mechanical fatigue of laser beam welded conventionally cast Inconel 738, directionally solidified Ren� 80 and single crystal Ren� N5 has been evaluated.� (more)
Durocher, Jonathan
Application of the U.S. high cycle fatigue data base to wind turbine blade lifetime predictions
This paper demonstrates a methodology for predicting the service lifetime of wind turbine blades using the high-cycle fatigue data base for typical U.S. blade materials developed by Mandell, et al. (1995). The first step in the analysis is to normalize the data base (composed primarily of data obtained from specialized, relatively small coupons) with fatigue data from typical industrial laminates to obtain a Goodman Diagram that is suitable for analyzing wind turbine blades. The LIFE2 fatigue analysis code for wind turbines is then used for the fatigue analysis of a typical turbine blade with a known load spectrum. In the analysis, a linear damage model, Miner`s Rule, is used to demonstrate the prediction of the service lifetime for a typical wind turbine blade under assumed operating strain ranges and stress concentration factors. In contrast to typical European data, the asymmetry in this data base predicts failures under typical loads to be compressive.
Sutherland, H.J. [Sandia National Labs., Albuquerque, NM (United States); Mandell, J.F. [Montana State Univ., Bozeman, MT (United States)
Proceedings of the 2000 International Conference on Fatigue of Reactor Components (MRP-46): PWR Materials Reliability Program (PWRMR P)
This report contains information presented at the First International Conference on Fatigue of Reactor Components held July 31 - August 2, 2000, in Napa, California. The conference -- sponsored by EPRI, the Organisation for Economic Co-operation and Development Nuclear Energy Agency/Committee on the Safety of Nuclear Installations (OECD NEA/CSNI), and the U.S. Nuclear Regulatory Commission (U.S. NRC) -- provided a forum for the technical discussion of fatigue issues that affect the integrity and operatio...
Method for forming metal contacts
Methods of forming metal contacts with metal inks in the manufacture of photovoltaic devices are disclosed. The metal inks are selectively deposited on semiconductor coatings by inkjet and aerosol apparatus. The composite is heated to selective temperatures where the metal inks burn through the coating to form an electrical contact with the semiconductor. Metal layers are then deposited on the electrical contacts by light induced or light assisted plating.
Reddington, Erik; Sutter, Thomas C; Bu, Lujia; Cannon, Alexandra; Habas, Susan E; Curtis, Calvin J; Miedaner, Alexander; Ginley, David S; Van Hest, Marinus Franciscus Antonius Maria
Liquid metal thermal electric converter
A liquid metal thermal electric converter which converts heat energy to electrical energy. The design of the liquid metal thermal electric converter incorporates a unique configuration which directs the metal fluid pressure to the outside of the tube which results in the structural loads in the tube to be compressive. A liquid metal thermal electric converter refluxing boiler with series connection of tubes and a multiple cell liquid metal thermal electric converter are also provided.
Abbin, Joseph P. (Albuquerque, NM); Andraka, Charles E. (Albuquerque, NM); Lukens, Laurance L. (Albuquerque, NM); Moreno, James B. (Albuquerque, NM)
Surface Studies of Ultra Strength Drilling Steel after Corrosion Fatigue in Simulated Sour Environment
The Unites States predicted 60% growth in energy demand by 2030 makes oil and natural gas primary target fuels for energy generation. The fact that the peak of oil production from shallow wells (industry into deeper wells. However, drilling to depths greater than 5000 m requires increasing the strength-to weight ratio of the drill pipe materials. Grade UD-165 is one of the ultra- high yield strength carbon steels developed for ultra deep drilling (UDD) activities. Drilling UDD wells exposes the drill pipes to Cl{sup -}, HCO{sub 3}{sup -}/CO{sub 3}{sup 2-}, and H{sub 2}S-containig corrosive environments (i.e., sour environments) at higher pressures and temperatures compared to those found in conventional wells. Because of the lack of synergism within the service environment, operational stresses can result in catastrophic brittle failures characteristic for environmentally assisted cracking (EAC). Approximately 75% of all drill string failures are caused by fatigue or corrosion fatigue. Since there is no literature data on the corrosion fatigue performance of UD-165 in sour environments, research was initiated to better clarify the fatigue crack growth (FCGR) behavior of this alloy in UDD environments. The FCGR behavior of ultra-strength carbon steel, grade UD-165, was investigated by monitoring crack growth rate in deaerated 5%NaCl solution buffered with NaHCO{sub 3}/Na{sub 2}CO{sub 3} and in contact with H{sub 2}S. The partial pressure of H{sub 2}S (p{sub H2S}) was 0.83 kPa and pH of the solution was adjusted by NaOH to 12. The fatigue experiments were performed at 20 and 85 C in an autoclave with surface investigations augmented by scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectroscopy. In this study, research focused on surface analyses supported by the fatigue crack growth rate measurements. Fig. 1 shows an SEM micrograph of the crack that propagated from the notch in the solution at 20 C. Accumulation of the corrosion products is visible along the crack. The EDX chemical analysis near the crack tip found iron, sulfur and oxygen in the passive layer. The surface of the sample after the fatigue test in the sour environment at 85{sup o}, Fig. 2, C looks different from that fatigued surface at 20 C. The crack propagates across the passive film that covers the surface fairly uniformly. Some spallation of the passive film is observed near the notch. The EDX chemical analysis of the passive film near the crack tip identified mainly iron, carbon and oxygen. It appears that temperature plays a very important role in formation of the passive film. This may be associated with different solubility of H{sub 2}S in the solution, which will be further studied.
M. Ziomek-Moroz; J.A. Hawk; R. Thodla; F. Gui
The Unites States predicted 60% growth in energy demand by 2030 makes oil and natural gas primary target fuels for energy generation. The fact that the peak of oil production from shallow wells (< 5000 m) is about to be reached, thereby pushing the oil and natural gas industry into deeper wells. However, drilling to depths greater than 5000 m requires increasing the strength-to weight ratio of the drill pipe materials. Grade UD-165 is one of the ultra- high yield strength carbon steels developed for ultra deep drilling (UDD) activities. Drilling UDD wells exposes the drill pipes to Cl{sup -}, HCO{sub 3}{sup -}/CO{sub 3}{sup 2-}, and H{sub 2}S-containig corrosive environments (i.e., sour environments) at higher pressures and temperatures compared to those found in conventional wells. Because of the lack of synergism within the service environment, operational stresses can result in catastrophic brittle failures characteristic for environmentally assisted cracking (EAC). Approximately 75% of all drill string failures are caused by fatigue or corrosion fatigue. Since there is no literature data on the corrosion fatigue performance of UD-165 in sour environments, research was initiated to better clarify the fatigue crack growth (FCGR) behavior of this alloy in UDD environments. The FCGR behavior of ultra-strength carbon steel, grade UD-165, was investigated by monitoring crack growth rate in deaerated 5%NaCl solution buffered with NaHCO{sub 3}/Na{sub 2}CO{sub 3} and in contact with H{sub 2}S. The partial pressure of H{sub 2}S (p{sub H2S}) was 0.83 kPa and pH of the solution was adjusted by NaOH to 12. The fatigue experiments were performed at 20 and 85 C in an autoclave with surface investigations augmented by scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectroscopy. In this study, research focused on surface analyses supported by the fatigue crack growth rate measurements. Fig. 1 shows an SEM micrograph of the crack that propagated from the notch in the solution at 20 C. Accumulation of the corrosion products is visible along the crack. The EDX chemical analysis near the crack tip found iron, sulfur and oxygen in the passive layer. The surface of the sample after the fatigue test in the sour environment at 85{sup o}, Fig. 2, C looks different from that fatigued surface at 20 C. The crack propagates across the passive film that covers the surface fairly uniformly. Some spallation of the passive film is observed near the notch. The EDX chemical analysis of the passive film near the crack tip identified mainly iron, carbon and oxygen. It appears that temperature plays a very important role in formation of the passive film. This may be associated with different solubility of H{sub 2}S in the solution, which will be further studied.
Approach to the fatigue analysis of vertical-axis wind-turbine blades
A cursory analysis of the stress history of wind turbine blades indicates that a single stress level at each wind speed does not adequately describe the blade stress history. A statistical description is required. Blade stress data collected from the DOE/ALCOA Low Cost experimental turbines indicate that the Rayleigh probability density function adequately describes the distribution of vibratory stresses at each wind speed. The Rayleigh probability density function allows the distribution of vibratory stresses to be described by the RMS of the stress vs. time signal. With the RMS stress level described for all wind speeds, the complete stress history of the turbine blades is known. Miner's linear cumulative damage rule is used as a basis for summing the fatigue damage over all operating conditions. An analytical expression is derived to predict blade fatigue life.
Thermal fatigue due to beam interruptions for an ALMR-type ATW
Accelerator-driven subcritical reactors have been proposed for tasks such as accelerator transmutation of waste (ATW). In such a device, long-lived radioactive fission products and transuranic elements from spent fuel would be converted into short-lived radioactive isotopes and stable isotopes. One concern about such devices is that current proton accelerators typically experience beam interruptions many times per day. The beam interruptions last from seconds to hours. A beam interruption leads to a temperature transient similar to, but faster than, that from a reactor scram. These temperature transients cause thermal fatigue that can eventually lead to structural failures in various reactor components. The objective of the work reported here was to determine the design implications of this thermal fatigue.
Dunn, F.E.
Procurement Specification for Horizontal Gas Path Heat Recovery Steam Generator: Avoiding Thermal-Mechanical Fatigue Damage
Many heat recovery steam generators (HRSGs), particularly those equipped with F-class gas turbines that are also subjected to periods of frequent cyclic operation, have experienced premature pressure part failures because of excessive thermal-mechanical fatigue (TMF) damage. The very competitive power generation marketplace has resulted in lowest installed cost often taking precedence over medium- and long-term durability and operating costs.
Materials Reliability Program: Third International Conference on Fatigue of Reactor Components (MRP-151)
These proceedings contain information presented at the Third International Conference on Fatigue of Reactor Components held October 3-6, 2004, in Seville, Spain. This third conference was again sponsored by EPRI, the Organisation for Economic Co-Operation and Development (OECD) Nuclear Energy Agency/Committee on the Safety of Nuclear Installations (NEA/CSNI), and the U. S. Nuclear Regulatory Commission (NRC) and hosted by Consejo de Segurida Nuclear (CNS) of Spain.
Mean Stress and Environmental Effects on Fatigue in Type 304 Stainless Steel
Fatigue life tests were performed in air on Type 304 stainless steel (304 SS) to establish the effect of mean stress under both load control and strain control. An apparent reduction of up to 26% in strain-amplitude occurred in the low and intermediate cycle regime (< 10{sup 8} cycles) for a mean stress of 138 Mpa. A quantitative description of mean stress effects using the Smith-Watson-Topper equivalent strain parameter was developed, which incorporates mean stress through the maximum stress. This description provided a tighter fit to the data, and allowed separation of mean stress and cold work effects. With this separation, the effect of mean stress was reduced to 12% decrease in strain amplitude at 138 Mpa. The stress-life curve apparently increased with increasing mean stress, due to the significant work hardening that occurred in tests with high mean stresses, especially under load control. Tests were performed on double-edge notched specimens of 304 SS in air and low oxygen water at 288 C. The elastically calculated increase in the notch tip stress accounted within 10% for the fatigue life reductions for a K{sub t} = 4.8 notch, but was 38% conservative for a K{sub t} = 8.8 notch. Fatigue crack initiation lives (defined as an 0.127 mm crack) in low oxygen water at 288 C were reduced by a factor of four to eight on cycles over those in air. Crack growth occurred throughout most of the fatigue ''initiation'' life. The increase in crack growth rate of 304 SS in water appears to be large enough to explain the reduced ''initiation'' life in this environment.
Kandra, J.T.; Leax, T.R.; Wire, G.L.
Steam Generator Management Program: Onset of Fatigue Cracking in Steam Generator Tubes With Through Wall Flaws
Leak rate tests of steam generator tubing with stress corrosion cracks and electrodischarge machining notches were conducted at Argonne National Laboratory (ANL) under the sponsorship of the U.S. Nuclear Regulatory Commission. Some test specimens displayed a significant leak rate increase under constant pressure hold. It was suspected that fatigue caused by jet�structure interaction was responsible for the increased leak rate. EPRI Reports 1015123 and 1016560 investigated the ANL test results in terms of...
Environmentally Assisted Fatigue (EAF) Screening: Process and Technical Basis for Identifying EAF Limiting Locations
This report provides the technical basis and process for a screening evaluation of a nuclear power plant. This screening will identify appropriate limiting locations for systematic monitoring of the environmentally assisted fatigue (EAF) effects in a Class 1 reactor on the reactor coolant pressure boundary components that are wetted with primary coolant. Use of this process will ensure that the most limiting locations for EAF are determined on a consistent basis.The process developed in ...
Method for locating metallic nitride inclusions in metallic alloy ingots
A method of determining the location and history of metallic nitride and/or oxynitride inclusions in metallic melts. The method includes the steps of labeling metallic nitride and/or oxynitride inclusions by making a coreduced metallic-hafnium sponge from a mixture of hafnium chloride and the chloride of a metal, reducing the mixed chlorides with magnesium, nitriding the hafnium-labeled metallic-hafnium sponge, and seeding the sponge to be melted with hafnium-labeled nitride inclusions. The ingots are neutron activated and the hafnium is located by radiometric means. Hafnium possesses exactly the proper metallurgical and radiochemical properties for this use.
White, Jack C. (Albany, OR); Traut, Davis E. (Corvallis, OR); Oden, Laurance L. (Albany, OR); Schmitt, Roman A. (Corvallis, OR)
A method is described for applying metallic coatings to a cylinder of uranium. An aluminum-silicon coat is applied by a process consisting of first cleaning the article by immersion for 5 minutes in 50% nitric acid at 65 C. The article then is dipped through a flux, prepared by adding 10% sodium fluoride to 90% of a flux comprising 53% potassium chloride, 42% lithium chloride, and 5% sodium chloride at 560 for 2 minutes and then directly into a molten metal bath comprising 99% aluminun and 12% silicon at 620 C for 3 minutes. While the coating is yet molten the article is transferred to a pair of steel rollers and rolled until the coating solidifies. By varying the composition of the flux other metals such as zinc, lead or the like may be coated on uranium in a similar manner.
Gage, H.A.
Transition-Metal Hydrides
Transition-Metal Hydride Electrochromics Transition-Metal Hydride Electrochromics A new type of electrochromic hydride material has interesting and unusual properties. Thin Ni-Mg films, for example, are mirror-like in appearance and have very low visible transmittance. On exposure to hydrogen gas or on reduction in alkaline electrolyte, the films become transparent. The transition is believed to result from formation of nickel magnesium hydride, Mg2NiH4. Switchable mirrors based on rare earth hydrides were discovered in 1996 at Vrije University in the Netherlands, Rare earth-magnesium alloy films were subsequently found to be superior to the pure lanthanides in maximum transparency and mirror-state reflectivity by Philips Laboratories. The newer transition-metal types which use less expensive and less reactive materials were discovered at LBNL. This has now become a very active area of study with a network of researchers.
Wind turbine blade fatigue tests: lessons learned and application to SHM system development
This paper presents experimental results of several structural health monitoring (SHM) methods applied to a 9-meter CX-100 wind turbine blade that underwent fatigue loading. The blade was instrumented with piezoelectric transducers, accelerometers, acoustic emission sensors, and foil strain gauges. It underwent harmonic excitation at its first natural frequency using a hydraulically actuated resonant excitation system. The blade was initially excited at 25% of its design load, and then with steadily increasing loads until it failed. Various data were collected between and during fatigue loading sessions. The data were measured over multiple frequency ranges using a variety of acquisition equipment, including off-the-shelf systems and specially designed hardware developed by the authors. Modal response, diffuse wave-field transfer functions, and ultrasonic guided wave methods were applied to assess the condition of the wind turbine blade. The piezoelectric sensors themselves were also monitored using a sensor diagnostics procedure. This paper summarizes experimental procedures and results, focusing particularly on fatigue crack detection, and concludes with considerations for implementing such damage identification systems, which will be used as a guideline for future SHM system development for operating wind turbine blades.
Taylor, Stuart G. [Los Alamos National Laboratory; Farinholt, Kevin M. [Los Alamos National Laboratory; Jeong, Hyomi [Chonbuk National University, Korea; Jang, JaeKyung [Chonbuk National University, Korea; Park, Gyu Hae [Los Alamos National Laboratory; Todd, Michael D. [Los Alamos National Laboratory; Farrar, Charles R. [Los Alamos National Laboratory; Ammerman, Curtt N. [Los Alamos National Laboratory
A generalized fitting technique for the LIFE2 fatigue analysis code
The analysis of component fatigue lifetime for a wind energy conversion system (WECS) requires that the component load spectrum be formulated in terms of stress cycles. Typically, these stress cycles are obtained from time series data using a cycle identification scheme. As discussed by many authors, the matrix or matrices of cycle counts that describe the stresses on a turbine are constructed from relatively short, representative samples of time series data. The ability to correctly represent the long-term behavior of the distribution of stress cycles from these representative samples is critical to the analysis of service lifetimes. Several techniques are currently used to convert representative samples to the lifetime cyclic loads on the turbine. There has been recently developed a set of fitting algorithms that is particularly useful for matching the body of the distribution of fatigue stress cycles on a turbine component. Fitting techniques are now incorporated into the LIFE2 fatigue/fracture analysis code for wind turbines. In this paper, the authors provide an overview of the fitting algorithms and describe the pre- and post-count algorithms developed to permit their use in the LIFE2 code. Typical case studies are used to illustrate the use of the technique.
Sutherland, H.J. [Sandia National Labs., Albuquerque, NM (United States). Wind Energy Research Dept.; Wilson, T. [Univ. of New Mexico, Albuquerque, NM (United States). New Mexico Engineering Research Inst.
Fatigue failure of regenerator screens in a high frequency Stirling engine
Failure of Stirling Space Power Demonstrator Engine (SPDE) regenerator screens was investigated. After several hours of operation the SPDE was shut down for inspection and upon removal of the regenerator screens, debris of an unknown origin was discovered along with considerable cracking of the screens in localized areas. Metallurgical analysis of the debris determined it to be cracked-off-deformed pieces of the 41 pm thickness Type 304 stainless steel wire screen. Scanning electron microscopy of the cracked screens revealed failures occurring at wire crossovers and fatigue striations on the fracture surface of the wires. Thus, the screen failure can be characterized as a fatigue failure of the wires. The crossovers were determined to contain a 30 percent reduction in wire thickness and a highly worked microstructure occurring from the manufacturing process of the wire screens. Later it was found that reduction in wire thickness occurred because the screen fabricator had subjected the screen to a light cold-roll process after weaving. Installation of this screen left a clearance in the regenerator allowing the screens to move. The combined effects of the reduction in wire thickness, stress concentration (caused by screen movement), and highly worked microstructure at the wire crossovers led to the fatigue failure of the screens.
Hull, D.R.; Alger, D.L.; Moore, T.J.; Sheuermann, C.M.
Fatigue Testing of 9 m Carbon Fiber Wind Turbine Research Blades
Fatigue testing was conducted on Carbon Experimental and Twist-Bend Experimental (CX-100 and TX-100) 9-m wind turbine research blades. The CX-100 blade was designed to investigate the use of a carbon spar cap to reduce weight and increase stiffness while being incorporated using conventional manufacturing techniques. The TX-100 blade used carbon in the outboard portion of the skin to produce twist-bend coupling to passively alleviate aerodynamic loads. In the fatigue tests, the CX-100 blade was loaded by a single hydraulic cylinder while the TX-100 blade was loaded via a hydraulically-actuated resonant loading system called the Universal Resonant Exciter. The blades were outfitted with approximately 30 strain gages as well as displacement and load sensors. Both blades survived to cycle counts sufficient to demonstrate a 20-year operational life. The CX-100 blade failed at approximately 1.6 million cycles because of a buckle and crack that formed and grew just outboard of max-chord. The TX-100 blade failed because of a crack that grew from the termination point of the spar cap at the midspan of the blade. This paper covers the results of the fatigue tests.
Paquette, J.; van Dam, J.; Hughes, S.; Johnson, J.
Hydrogen induced surface cracking in an 8090 Al-Li alloy during high cycle fatigue
In recent years, there has been an increasing interest in understanding the effects of aggressive or moist environments on the properties of Al-Li alloys. However, most of the existing work has been focused on their stress corrosion cracking resistance. Consequently, only a few reports are available on the environmental fatigue strength of these alloys. Upon exposure to aggressive environments, the fatigue crack propagation resistance can be detrimentally affected. R. Piascik and R. Gangloff found enhanced cyclic crack growth rates in an Al-Li-Cu alloy when a critical water vapor pressure was exceeded. Thermodynamically, at atmospheric pressures, strong interactions between hydrogen and lithium are expected to give rise to stable lithium hydrides. Evidence for the development of hydride phases in Al-Li alloys exposed to hydrogen environments has been reported by various workers. Thus, it is likely that HE via hydride formation can be the relevant mechanisms in Al-Li alloys that have been in contact with hydrogen. Since lithium hydrides are stable up to temperatures of 773 K, previous hydrogen exposure can lead to an irreversible mode of embrittlement. Thus, it was the objective of the present work to investigate the effects of hydrogen during aging on the ensuing high cycle fatigue (HCF) performance of an 8090 Al-Li alloy.
Laffin, C.; Raghunath, C.R.; Lopez, H.F. (Univ. of Wisconsin, Milwaukee, WI (United States). Materials Dept.)
Frequency-Domain Synthesis Of The Fatigue Load Spectrum For The Nps 100-Kw Wind Turbine
* The LIFE2 code is a fatigue/fracture mechanics code that is specialized to the analysis of wind turbine components. Two frequency-domain stress spectra techniques contained in this code are used to analyze the measured frequency loads spectra from the Northern Power Systems 100-kW turbine. Results of the two techniques are compared to cycle counts obtained directly from time series data. These results provide the wind turbine designer with two techniques for determining the cycle-counts from frequency data and illustrate the accuracy that the designer can expect from various cycle-counting techniques. INTRODUCTION The LIFE2 code is a fatigue/fracture mechanics code that is specialized to the analysis of wind turbine components. 1 This code permits the analysis of both time series 2 and frequency domain data. 3 In the case of the former, a "rainflow counting" algorithm is used to convert time series data into a cycle count matrix suitable for fatigue analysis. For the latter,...
Herbert J. Sutherland; Richard M. Osgood
Effect of Load Phase Angle on Wind Turbine Blade Fatigue Damage: Preprint
This paper examines the importance of phase angle variations with respect to fatigue damage. The operating loads on a generic conventional three-bladed upwind 1.5-MW wind turbine blade were analyzed over a range of operating conditions, and an aggregate probability distribution for the actual phase angles between the in-plane (lead-lag) and out-of-plane (flap) loads was determined. Using a finite element model of a generic blade and Miner's Rule, the accumulated theoretical damage (based on axial strains) resulting from a fatigue test with variable phase angles was compared to the damage resulting from a fatigue test with a constant phase angle. The nodal damage distribution at specific blade cross-sections are compared for the constant and variable phase angle cases. The sequence effects of various phase angle progressions were also considered. For this analysis, the finite element results were processed using the nonlinear Marco-Starkey damage accumulation model. Each phase angle sequence was constrained to have the same overall phase angle distribution and the same total number of cycles but the order in which the phase angles were applied was varied.
White, D. L.; Musial, W. D.
Catalysis Without Precious Metals
Written for chemists in industry and academia, this ready reference and handbook summarizes recent progress in the development of new catalysts that do not require precious metals. The research thus presented points the way to how new catalysts may ultimately supplant the use of precious metals in some types of reactions, while highlighting the remaining challenges. This material is based upon work supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences.
Bullock, R. Morris
Metal alloy identifier
To identify the composition of a metal alloy, sparks generated from the alloy are optically observed and spectrographically analyzed. The spectrographic data, in the form of a full-spectrum plot of intensity versus wavelength, provide the "signature" of the metal alloy. This signature can be compared with similar plots for alloys of known composition to establish the unknown composition by a positive match with a known alloy. An alternative method is to form intensity ratios for pairs of predetermined wavelengths within the observed spectrum and to then compare the values of such ratios with similar values for known alloy compositions, thereby to positively identify the unknown alloy composition.
Riley, William D. (Avondale, MD); Brown, Jr., Robert D. (Avondale, MD)
Metallic carbon materials
Novel metallic forms of planar carbon are described, as well as methods of designing and making them. Nonhexagonal arrangements of carbon are introduced into a graphite carbon network essentially without destroying the planar structure. Specifically a form of carbon comprising primarily pentagons and heptagons, and having a large density of states at the Fermi level is described. Other arrangements of pentagons and heptagons that include some hexagons, and structures incorporating squares and octagons are additionally disclosed. Reducing the bond angle symmetry associated with a hexagonal arrangement of carbons increases the likelihood that the carbon material will have a metallic electron structure.
Cohen, Marvin Lou (Berkeley, CA); Crespi, Vincent Henry (Darien, IL); Louie, Steven Gwon Sheng (Berkeley, CA); Zettl, Alexander Karlwalter (Kensington, CA)
Cyclic fatigue and resistance-curve behavior of an in situ toughened silicon carbide with Al-B-C additions
The room-temperature crack-growth properties of an in situ toughened, monolithic silicon carbide are reported. Hot pressing was performed at 1900 C with 3 wt.% Al, 2 wt.% C and 0.6 wt.% B additions. Compared to a commercial SiC (Hexoloy SA), significant improvements in both the fracture toughness and cyclic fatigue-crack propagation resistance have been achieved through control of the {beta} to {alpha} transformation. Using fatigue-precracked, disk-shaped compact-tension specimens, marked rising resistance-curve behavior was measured over the first {approximately}600 {micro}m of crack extension, leading to a plateau fracture toughness of K{sub c} {approximately} 9.1 MPa{radical}m; this represents more than a threefold increase over the toughness of Hexoloy, where a K{sub c} value of 2.5 MPa{radical}m was measured with no evidence of a resistance curve. Cyclic fatigue-crack growth rates in the toughened SiC were found to be faster than those under sustained loads (static fatigue) at the same stress-intensity level. The cyclic fatigue-crack growth resistance was found to be far superior to that of Hexoloy. Whereas cracking in the commercial SiC became unstable when the maximum stress intensity K{sub max} exceeded {approximately}2 MPa{radical}m, thresholds for fatigue-crack growth in the in situ toughened material exceeded a K{sub max} of 7 MPa{radical}m. Such dramatic improvements in the crack-growth resistance of SiC are attributed to a microstructure consisting of a network of interlocking, plate-like predominantly {alpha}-phase grains, which combine to both bridge and deflect the crack. These results represent the first reported evidence of cyclic fatigue behavior in a monolithic silicon carbide and the first direct measurement of the resistance curve properties in this ceramic.
Gilbert, C.J.; Cao, J.J.; Moberlychan, W.J.; DeJonghe, L.C.; Ritchie, R.O. [Lawrence Berkeley Lab., CA (United States). Materials Science Div.]|[Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering
Weld Metal Metallurgical Handbook
This report is part of an ongoing series of metallurgical handbooks that are being developed for utility engineers to use in assessing metallurgical characteristics of any given alloy. This report focuses specifically on the weld metal metallurgical characteristics of carbon, low-alloy martensitic, and austenitic stainless steel welds.
Serpentine metal gasket
A metallic seal or gasket for use in the joining of cryogenic fluid conduits, the seal or gasket having a generally planar and serpentine periphery defining a central aperture. According to a preferred embodiment, the periphery has at least two opposing elongated serpentine sides and two opposing arcuate ends joining the opposing elongated serpentine sides and is of a hexagonal cross-section.
Rothgeb, Timothy Moore (Norfolk, VA); Reece, Charles Edwin (Yorktown, VA)
Metal halogen electrochemical cell
It has now been discovered that reduction in the coulombic efficiency of metal halogen cells can be minimized if the microporous separator employed in such cells is selected from one which is preferably wet by the aqueous electrolyte and is not wet substantially by the cathodic halogen.
Bellows, Richard J. (Hampton, NJ); Kantner, Edward (E. Brunswick, NJ)
A method is described for removing aluminumuranium-silicon alloy bonded to metallic U comprising subjecting the Al-U -Si alloy to treatment with hot concentrated HNO/sun 3/ to partially dissolve and embrittle the alloy and shot- blasting the embrittled alloy to loosen it from the U.
Siefen, H.T.; Campbell, J.M.
Ductile transplutonium metal alloys
Alloys of Ce with transplutonium metals such as Am, Cm, Bk and Cf have properties making them highly suitable as souces of the transplutonium element, e.g., for use in radiation detector technology or as radiation sources. The alloys are ductile, homogeneous, easy to prepare and have a fairly high density.
Conner, W.V.
Recipients: The 2001 LMD Light Metals Award
The Minerals, Metals & Materials Society's Light Metals Division Light Metals Award, established in 1983, is awarded to the author(s) of a paper published in the�...
Recipients: The 2003 LMD Light Metals Award
Recipients: The 2002 LMD Light Metals Award
Recipients: The 2004 LMD Light Metals Award
Functional Metal Phosphonates
The primary goal of the work described in this dissertation was the incorporation of functionality into metal phosphonates. This was done in one of several ways. The first involved using phosphonate ligands that had covalently attached organic functional groups. In some cases, these ligands undergo reactions during the solvothermal syntheses which can impart new chemical reactivity. Another method used to introduce functionality was to partially or completely substitute metal atoms within phosphonate clusters to create materials which may have interesting magnetic properties. By controlling the way these clusters pack in the solids, their magnetic properties may be able to be augmented. The final method used to impart functionality to metal phosphonates was the incorporation of N-donor and bulky aryl groups into the phosphonate ligands. These influences caused structural variations which exposed potentially active sites within the materials, including both Lewis acidic and basic sites, as well as Bronsted acid sites. The first strategy was employed in the design of tetravalent metal phosphonates which have covalently incorporated bipyridine moieties. The materials are porous so that the bipyridine sites can chelate Pd atoms from solution, which can then be reduced to stable nanoparticles trapped within the phosphonate matrix. This approach was also used in the synthesis of surface-functionalized divalent metal phosphonates which exhibit interesting amine uptake properties. Solvent and cation substitution effects were used to control the packing and connectivity of phosphonate-based clusters. The selective substitution of metal atoms within the clusters may lead to interesting magnetic materials. In other work, N-donor and bulky phosphonates were used to influence the structure of several SnII phosphonates, which resulted in the discovery of a new layered structure type. The effect of the Sn-N interaction on the structures is investigated, and found to have significant effects on the structural units formed and how they pack in the solid state. The work presented herein represents only a small fraction of the rich chemistry of metal phosphonates. Creative researchers will continue to push boundaries and find new and interesting applications for phosphonate-based materials.
Perry, Houston Phillipp
Purification of alkali metal nitrates
A process is disclosed for removing heavy metal contaminants from impure alkali metal nitrates containing them. The process comprises mixing the impure nitrates with sufficient water to form a concentrated aqueous solution of the impure nitrates, adjusting the pH of the resulting solution to within the range of between about 2 and about 7, adding sufficient reducing agent to react with heavy metal contaminants within said solution, adjusting the pH of the solution containing reducing agent to effect precipitation of heavy metal impurities and separating the solid impurities from the resulting purified aqueous solution of alkali metal nitrates. The resulting purified solution of alkali metal nitrates may be heated to evaporate water therefrom to produce purified molten alkali metal nitrate suitable for use as a heat transfer medium. If desired, the purified molten form may be granulated and cooled to form discrete solid particles of alkali metal nitrates.
Fiorucci, Louis C. (Hamden, CT); Gregory, Kevin M. (Woodridge, IL)
Metal reduction kinetics in Shewanella
Motivation: Metal reduction kinetics have been studied in cultures of dissimilatory metal reducing bacteria which include the Shewanella oneidensis strain MR-1. Estimation of system parameters from time-series data faces obstructions in ...
Raman Lall; Julie Mitchell
Metal-Ion-Mediated Reactions
Metal-Ion-Mediated Reactions Metal-Ion-Mediated Reactions Metal-Ion-Mediated Reactions Print Monday, 19 December 2011 18:29 While mononuclear, polynuclear, and polymeric metal complexes are most often synthesized by the reaction of a metal precursor and a presynthesized organic ligand, it is also possible to generate the ligand in situ from an easily available organic compound. This approach allows the reactivity of the metal ion to activate a proligand, transforming it through an in situ reaction, sometimes providing coordination compounds with ligands not accessible by conventional organic synthesis. The intense interest in the reactivity of coordinated ligands is mainly due to the necessity of interpreting the mechanisms of homogeneous metal-catalyzed processes, in which a substrate is activated upon its coordination to one or more metal sites. A coordinated oxime group contains three active sites (C, N, O) for reactivity.
The treatment of metallic uranium to provide a surface to which adherent electroplates can be applied is described. Metallic uranium is subjected to an etchant treatment in aqueous concentrated hydrochloric acid, and the etched metal is then treated to dissolve the resulting black oxide and/or chloride film without destroying the etched metal surface. The oxide or chloride removal is effected by means of moderately concentrated nitric acid in 3 to 20 seconds.
Gray, A.G.; Schweikher, E.W.
Electroless metal plating of plastics
Process for plating main group metals on aromatic polymers is carried out by the use of a nonaqueous solution of a salt of an alkali metal in a positive valence state and a main group metal in a negative valence state with contact between the solution and polymer providing a redox reaction causing the deposition of the main group metal and the reduction of the polymer. Products from the process exhibit useful decorative and electrical properties.
Krause, L.J.
Inert electrode containing metal oxides, copper and noble metal
A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.
Ray, Siba P. (Murrysville, PA); Woods, Robert W. (New Kensington, PA); Dawless, Robert K. (Monroeville, PA); Hosler, Robert B. (Sarver, PA)
The removal of lmpurities from uranlum metal can be done by a process conslstlng of contacting the metal with liquid mercury at 300 icient laborato C, separating the impunitycontalnlng slag formed, cooling the slag-free liquld substantlally below the point at which uranlum mercurlde sollds form, removlng the mercury from the solids, and recovering metallic uranium by heating the solids.
Blanco, R.E.; Morrison, B.H.
Fabrication of metallic glass structures
Amorphous metal powders or ribbons are fabricated into solid shapes of appreciable thickness by the application of compaction energy. The temperature regime wherein the amorphous metal deforms by viscous flow is measured. The metal powders or ribbons are compacted within the temperature regime.
Cline, C.F.
Integrated decontamination process for metals
An integrated process for decontamination of metals, particularly metals that are used in the nuclear energy industry contaminated with radioactive material. The process combines the processes of electrorefining and melt refining to purify metals that can be decontaminated using either electrorefining or melt refining processes.
Snyder, Thomas S. (Oakmont, PA); Whitlow, Graham A. (Murrysville, PA)
Effects of neutron irradiation on fatigue and creep-fatigue crack propagation in type 316 stainless steel at 649 degree C produced no significant effect on the crack propagation rate when compared with unirradiated steel tested at 649 degree C
The fatigue and creep-fatigue crack propagation performance of Type 316 stainless steel has been investigated following fast neutron (n) irradiation. The purpose was to evaluate the effects of neutron fluence and temperature on the crack propagation resistance and failure mode of the steel. Results are presented from fatigue tests of the annealed steel that were irradiated at 649 degree C Scanning electron microscope examination of the fracture surfaces of the tested specimens revealed that the failure mode of the specimens which exhibited increased crack propagation rates was primarily intergranular while a transgranular mode was observed for specimens with lower crack propagation rates. The results point toward a synergistic relationship between thermomechanical history, precipitate formation, and hold time effects as the responsible mechanism for the crack propagation performance.
Michel, D.J.; Smith, H.H.
A process of reducing actinide oxide to the metal with magnesium-zinc alloy in a flux of 5 mole% of magnesium fluoride and 95 mole% of magnesium chloride plus lithium, sodium, potassium, calcium, strontium, or barium chloride is presented. The flux contains at least 14 mole% of magnesium cation at 600-- 900 deg C in air. The formed magnesium-zinc-actinide alloy is separated from the magnesium-oxide-containing flux. (AEC)
Knighton, J.B.
A method is presented for restoring the effectiveness of bronze coating baths used for hot dip coating of uranium. Such baths, containing a high proportion of copper, lose their ability to wet uranium surfaces after a period of use. The ability of such a bath to wet uranium can be restored by adding a small amount of metallic aluminum to the bath, and skimming the resultant hard alloy from the surface.
Robinson, J.W.
Spray casting of metallic preforms
A metal alloy is melted in a crucible and ejected from the bottom of the crucible as a descending stream of molten metal. The descending stream is impacted with a plurality of primary inert gas jets surrounding the molten metal stream to produce a plume of atomized molten metal droplets. An inert gas is blown onto a lower portion of the plume with a plurality of auxiliary inert gas jets to deflect the plume into a more restricted pattern of high droplet density, thereby substantially eliminating unwanted overspray and resulting wasted material. The plume is projected onto a moving substrate to form a monolithic metallic product having generally parallel sides.
Flinn, John E. (Idaho Falls, ID); Burch, Joseph V. (Shelley, ID); Sears, James W. (Niskayuna, NY)
Liquid Metal Processing and Casting 2013
Ceramic, Slag and Refractory Reactions with Liquid Metals - Refining, Evaporation and Gas/Metal Reactions - Fundamentals of Reactions involving Liquid�...
Recycling Metals for the Environment - TMS
Jun 26, 2008 ... This article describes metal production from primary and secondary resources, recovering metals from waste streams and environmental�...
Compositions and methods of making are provided for mesoporous metal oxide microspheres electrodes. The mesoporous metal oxide microsphere ...
Materials Sustainability: Digital Resource Center - Recycling Metals ...
Jul 2, 2008 ... This article describes metal production from primary and secondary resources, recovering metals from waste streams and environmental�...
Simulation System on the Thermal Stress and Fatigue Life Loss of Startup and Shutdown for a Domestic 600MW Steam Turbo Generator Unit
The Simulation System on the thermal stresses and fatigue life loss of the rotator during startup and shutdown for a domestic 600MW steam turbo generator unit, By means of the analysis of Simulation System on the thermal stress and life loss of the rotor, ... Keywords: steam turbine unit, thermal stress, Fatigue Life Loss, rotator, startup, shutdown
Yunchun Xia
Hydrothermal alkali metal recovery process
In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles by treating them with a calcium or magnesium-containing compound in the presence of water at a temperature between about 250/sup 0/F and about 700/sup 0/F and in the presence of an added base to establish a pH during the treatment step that is higher than would otherwise be possible without the addition of the base. During the treating process the relatively high pH facilitates the conversion of water-insoluble alkali metal compounds in the alkali metal residues into water-soluble alkali metal constituents. The resultant aqueous solution containing watersoluble alkali metal constituents is then separated from the residue solids, which consist of the treated particles and any insoluble materials formed during the treatment step, and recycled to the gasification process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst. Preferably, the base that is added during the treatment step is an alkali metal hydroxide obtained by water washing the residue solids produced during the treatment step.
Clavenna, L.R.; Eakman, J.M.; Kalina, T.; Wolfs, D.Y.
In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles by treating them with a calcium or magnesium-containing compound in the presence of water at a temperature between about 250.degree. F. and about 700.degree. F. and in the presence of an added base to establish a pH during the treatment step that is higher than would otherwise be possible without the addition of the base. During the treating process the relatively high pH facilitates the conversion of water-insoluble alkali metal compounds in the alkali metal residues into water-soluble alkali metal constituents. The resultant aqueous solution containing water-soluble alkali metal constituents is then separated from the residue solids, which consist of the treated particles and any insoluble materials formed during the treatment step, and recycled to the gasification process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst. Preferably, the base that is added during the treatment step is an alkali metal hydroxide obtained by water washing the residue solids produced during the treatment step.
Wolfs, Denise Y. (Houston, TX); Clavenna, Le Roy R. (Baytown, TX); Eakman, James M. (Houston, TX); Kalina, Theodore (Morris Plains, NJ)
Dimensionally stable metallic hydride composition
A stable, metallic hydride composition and a process for making such a composition. The composition comprises a uniformly blended mixture of a metal hydride, kieselguhr, and a ballast metal, all in the form of particles. The composition is made by subjecting a metal hydride to one or more hydrogen absorption/desorption cycles to disintegrate the hydride particles to less than approximately 100 microns in size. The particles are partly oxidized, then blended with the ballast metal and the kieselguhr to form a uniform mixture. The mixture is compressed into pellets and calcined. Preferably, the mixture includes approximately 10 vol. % or more kieselguhr and approximately 50 vol. % or more ballast. Metal hydrides that can be used in the composition include Zr, Ti, V, Nb, Pd, as well as binary, tertiary, and more complex alloys of La, Al, Cu, Ti, Co, Ni, Fe, Zr, Mg, Ca, Mn, and mixtures and other combinations thereof. Ballast metals include Al, Cu and Ni.
Heung, Leung K. (Aiken, SC)
A stable, metallic hydride composition and a process for making such a composition are described. The composition comprises a uniformly blended mixture of a metal hydride, kieselguhr, and a ballast metal, all in the form of particles. The composition is made by subjecting a metal hydride to one or more hydrogen absorption/desorption cycles to disintegrate the hydride particles to less than approximately 100 microns in size. The particles are partly oxidized, then blended with the ballast metal and the kieselguhr to form a uniform mixture. The mixture is compressed into pellets and calcined. Preferably, the mixture includes approximately 10 vol. % or more kieselguhr and approximately 50 vol. % or more ballast. Metal hydrides that can be used in the composition include Zr, Ti, V, Nb, Pd, as well as binary, tertiary, and more complex alloys of La, Al, Cu, Ti, Co, Ni, Fe, Zr, Mg, Ca, Mn, and mixtures and other combinations thereof. Ballast metals include Al, Cu and Ni.
Heung, L.K.
Corrosion Resistant Metallic Materials for Ultra-deep Well Drilling ...
... corrosion fatigue, etc., can be a primary cause of catastrophic degradation of tubular components during ultra-deep drilling of oil and natural gas shale.
Reduction of Metal Oxide to Metal using Ionic Liquids
A novel pathway for the high efficiency production of metal from metal oxide means of electrolysis in ionic liquids at low temperature was investigated. The main emphasis was to eliminate the use of carbon and high temperature application in the reduction of metal oxides to metals. The emphasis of this research was to produce metals such as Zn, and Pb that are normally produced by the application of very high temperatures. The reduction of zinc oxide to zinc and lead oxide to lead were investigated. This study involved three steps in accomplishing the final goal of reduction of metal oxide to metal using ionic liquids: 1) Dissolution of metal oxide in an ionic liquid, 2) Determination of reduction potential using cyclic voltammetry (CV) and 3) Reduction of the dissolved metal oxide. Ionic liquids provide additional advantage by offering a wide potential range for the deposition. In each and every step of the process, more than one process variable has been examined. Experimental results for electrochemical extraction of Zn from ZnO and Pb from PbO using eutectic mixtures of Urea ((NH2)2CO) and Choline chloride (HOC2H4N(CH3)3+Cl-) or (ChCl) in a molar ratio 2:1, varying voltage and temperatures were carried out. Fourier Transform Infra-Red (FTIR) spectroscopy studies of ionic liquids with and without metal oxide additions were conducted. FTIR and induction coupled plasma spectroscopy (ICPS) was used in the characterization of the metal oxide dissolved ionic liquid. Electrochemical experiments were conducted using EG&G potentiostat/galvanostat with three electrode cell systems. Cyclic voltammetry was used in the determination of reduction potentials for the deposition of metals. Chronoamperometric experiments were carried out in the potential range of -0.6V to -1.9V for lead and -1.4V to -1.9V for zinc. The deposits were characterized using XRD and SEM-EDS for phase, morphological and elemental analysis. The results showed that pure metal was deposited on the cathode. Successful extraction of metal from metal oxide dissolved in Urea/ChCl (2:1) was accomplished. The current efficiencies were relatively high in both the metal deposition processes with current efficiency greater than 86% for lead and 95% for zinc. This technology will advance the metal oxide reduction process by increasing the process efficiency and also eliminate the production of CO2 which makes this an environmentally benign technology for metal extraction.
Dr. Ramana Reddy
Corrosion protective coating for metallic materials
Corrosion protective coatings for metallic materials, particularly aluminum and aluminum alloys, produced with simple, low-cost equipment and materials other than toxic metals or metal salts, or metal cyanides. The metallic material is cleaned, degreased, and deoxidized, the surface is converted to a substantially alkaline condition, and the surface is chemically sealed with inorganic metal compounds.
Buchheit, Rudolph G. (Albuquerque, NM); Martinez, Michael A. (Albuquerque, NM)
Effect of aging on the fatigue crack growth kinetics of an Al-Zn-Mg-Cu alloy in two directions
There have been investigations discussing the effect of aging condition, and thereby the microstructure, on the fatigue crack growth characteristics of precipitation hardening alloys. Lindigkeit et al.., testing an Al-Zn-Mg-Cu alloy of composition corresponding to the commercial alloy 7075 concluded that the crack propagation resistance of underaged microstructures with shearable precipitates is significantly higher than overaged samples of same strength containing non-shearable particles. They reported that this behavior cannot be explained on the basis of slip reversibility alone. A similar conclusion is drawn by Zaiken and Ritchie from investigations on the effect of microstructure on the fatigue crack growth rate of an 7150 aluminum alloy, which is a somewhat high-purity version of the alloy 7050, with lower Fe and Si contents. It is also interesting that aging conditions showing high resistance to fatigue crack growth at low [Delta]K regimes, do not necessarily retain their superiority at medium and high stress intensity ranges.
Alpay, S.P.; Guerbuez, R. (Middle East Technical Univ., Ankara (Turkey). Dept. of Metallurgical Engineering)
Fatigue damage estimate comparisons for northern European and U.S. wind farm loading environments
Typical loading histories associated with wind turbine service environments in northern Europe and within a large wind farm in the continental US were recently compared by Kelley (1995) using the WISPER [Ten Have, 1992] loading standard and its development protocol. In this study, an equivalent load spectrum for a US wind farm was developed by applying the WISPER development protocol to representative service load histories collected from two adjacent turbines operating within a large wind farm in San Gorgonio Pass, California. The results of this study showed that turbines operating in the California wind farm experience many more loading cycles with larger peak-to-peak values for the same mean wind speed classification than their European counterparts. In this paper, the impact of the two WISPER-protocol fatigue-load spectra on service lifetime predictions are used to compare and contrast the impact of the two loading environments with one another. The service lifetime predictions are made using the LIFE2 Fatigue Analysis Code [Sutherland and Schluter, 1989] with the fatigue properties of typical fiber glass composite blade materials. Additional analyses, based on rainflow counted time histories from the San Gorgonio turbines, are also used in the comparisons. In general, these results indicate that the WISPER load spectrum from northern European sites significantly underestimates the WISPER protocol load spectrum from a US wind farm site; i.e., the WISPER load spectrum significantly underestimates the number and magnitude of the loads observed at a US wind farm site. The authors conclude that there are fundamental differences in the two service environments.
Sutherland, H.J. [Sandia National Labs., Albuquerque, NM (United States). Wind Energy Technology Dept.; Kelley, N.D. [National Renewable Energy Lab., Golden, CO (United States). Wind Technology Div.
Fatigue Crack Propagation from Notched Specimens of 304 SS in elevated Temperature Aqueous Environment
Fatigue crack propagation (FCP) rates for 304 stainless steel (304SS) were determined in 24 degree C and 288 degree C air and 288 degree C water using double-edged notch (DEN) specimens of 304 stainless steel (304 SS). Test performed at matched loading conditions in air and water at 288 degree C with 20-6- cc h[sub]2/kg h[sub]2O provided a direct comparison of the relative crack growth rates in air and water over a wide range of crack growth rates. The DEN crack extension ranged from short cracks (0.03-0.25 mm) to long cracks up to 4.06 mm, which are consistent with conventional deep crack tests. Crack growth rates of 304 SS in water were about 12 times the air rate. This 12X environmental enhancement persisted to crack extensions up to 4.06 mm, far outside the range associated with short crack effects. The large environmental degradation for 304 SS crack growth is consistent with the strong reduction of fatigue life in high hydrogen water. Further, very similar environmental effects w ere reported in fatigue crack growth tests in hydrogen water chemistry (HWC). Most literature data in high hydrogen water show only a mild environmental effect for 304 SS, of order 2.5 times air or less, but the tests were predominantly performed at high cyclic stress intensity or equivalently, high air rates. The environmental effect in low oxygen environments at low stress intensity depends strongly on both the stress ratio, R, and the load rise time, T[sub]r, as recently reported for austenitic stainless steel in BWR water. Fractography was performed for both tests in air and water. At 288 degree C in water, the fracture surfaces were crisply faceted with a crystallographic appearance, and showed striations under high magnification. The cleavage-like facets on the fracture surfaces suggest that hydrogen embrittlement is the primary cause of accelerated cracking.
Wire, G. L.; Mills, W. J.
Corrosion fatigue of iron-chromium-nickel alloys: Fracture mechanics, microstructure and chemistry
Phase transformation and cracking during RT aging of charged, high-purity Fe18Cr12Ni alloy and commerical 304 ss were examined; results show that [epsilon]* (hcp) hydride formed on Fe18Cr12Ni upon charging, and it decomposed rapidly to form first [epsilon] and then [alpha]' martensite. Morphology of fracture surfaces of Fe18Cr12Ni produced by corrosion fatigue in NaCl solutions and in hydrogen was found to be identical. Effort was made to examine the approaches and methodologies used in service life predictions and reliability analyses.
Wei, R.P.
Devastated crops: multifunctional efficacy for the production of nanoparticles
Integration of green chemistry principles to nanotechnology is one of the key issues in nanoscience research. Biological methods were used to synthesize metal and metal oxide nanoparticles of specific shape and size since they enhance the properties ...
G. Madhumitha, Selvaraj Mohana Roopan
Hydrogen reduces the service life of many metallic components. Such reductions may be manifested as blisters, as a decrease in fatigue resistance, as enhanced creep, as the precipitation of a hydride phase and, most commonly, as unexpected, macroscopically brittle failure. This unexpected, brittle fracture is commonly termed hydrogen embrittlement. Frequently, hydrogen embrittlement occurs after the component has been is service for a period of time and much of the resulting fracture surface is distinctly intergranular. Many failures, particularly of high strength steels, are attributed to hydrogen embrittlement simply because the failure analyst sees intergranular fracture in a component that served adequately for a significant period of time. Unfortunately, simply determining that a failure is due to hydrogen embrittlement or some other form of hydrogen induced damage is of no particular help to the customer unless that determination is coupled with recommendations that provide pathways to avoid such damage in future applications. This paper presents qualitative and phenomenological descriptions of the hydrogen damage processes and outlines several metallurgical recommendations that may help reduce the susceptibility of a particular component or system to the various forms of hydrogen damage.
Louthan, M
Pressure Resistance Welding of High Temperature Metallic Materials
Pressure Resistance Welding (PRW) is a solid state joining process used for various high temperature metallic materials (Oxide dispersion strengthened alloys of MA957, MA754; martensitic alloy HT-9, tungsten etc.) for advanced nuclear reactor applications. A new PRW machine has been installed at the Center for Advanced Energy Studies (CAES) in Idaho Falls for conducting joining research for nuclear applications. The key emphasis has been on understanding processing-microstructure-property relationships. Initial studies have shown that sound joints can be made between dissimilar materials such as MA957 alloy cladding tubes and HT-9 end plugs, and MA754 and HT-9 coupons. Limited burst testing of MA957/HT-9 joints carried out at various pressures up to 400oC has shown encouraging results in that the joint regions do not develop any cracking. Similar joint strength observations have also been made by performing simple bend tests. Detailed microstructural studies using SEM/EBSD tools and fatigue crack growth studies of MA754/HT-9 joints are ongoing.
N. Jerred; L. Zirker; I. Charit; J. Cole; M. Frary; D. Butt; M. Meyer; K. L. Murty
Impact Resistance of Carbon Fiber and Metallic Glass Fiber Metal ...
The combination of thin metallic sheets with carbon fiber composite results in a ... Ceramic Textile Composites under In Situ Loading at Ultrahigh Temperatures.
molecular coordination chemistry of CH3NC has been reported.features of this surface chemistry. ACKNOw"LEDGMENTS The1980 Catalysis~ COORDINATION CHEMISTRY OF METAL SURFACES AND
Muetterties, E.L.
Metal nanoparticle inks
Stabilized silver particles comprise particles comprising silver, a short-chain capping agent adsorbed on the particles, and a long-chain capping agent adsorbed on the particles. The short-chain capping agent is a first anionic polyelectrolyte having a molecular weight (Mw) of at most 10,000, and the long-chain capping agent is a second anionic polyelectrolyte having a molecular weight (Mw) of at least 25,000. The stabilized silver particles have a solid loading of metallic silver of at least 50 wt %.
Lewis, Jennifer A. (Urbana, IL); Ahn, Bok Yeop (Champaign, IL); Duoss, Eric B. (Urbana, IL)
Method of improving fatigue life of cast nickel based superalloys and composition
The invention consists of a method of producing a fine equiaxed grain structure (ASTM 2-4) in cast nickel-base superalloys which increases low cycle fatigue lives without detrimental effects on stress rupture properties to temperatures as high as 1800.degree. F. These superalloys are variations of the basic nickel-chromium matrix, hardened by gamma prime [Ni.sub.3 (Al, Ti)] but with optional additions of cobalt, tungsten, molybdenum, vanadium, columbium, tantalum, boron, zirconium, carbon and hafnium. The invention grain refines these alloys to ASTM 2 to 4 increasing low cycle fatigue life by a factor of 2 to 5 (i.e. life of 700 hours would be increased to 1400 to 3500 hours for a given stress) as a result of the addition of 0.01% to 0.2% of a member of the group consisting of boron, zirconium and mixtures thereof to aid heterogeneous nucleation. The alloy is vacuum melted and heated to 250.degree.-400.degree. F. above the melting temperature, cooled to partial solidification, thus resulting in said heterogeneous nucleation and fine grains, then reheated and cast at about 50.degree.-100.degree. F. of superheat. Additions of 0.1% boron and 0.1% zirconium (optional) are the preferred nucleating agents.
Denzine, Allen F. (Chardon, OH); Kolakowski, Thomas A. (Cleveland, OH); Wallace, John F. (Shaker Heights, OH)
Fatigue-crack propagation in aluminum-lithium alloys processed by power and ingot metallurgy
Fatigue-crack propagation behavior in powder-metallurgy (P/M) aluminum-lithium alloys, namely, mechanically-alloyed (MA) Al-4.0Mg-1.5Li-1.1C-0.80{sub 2} (Inco 905-XL) and rapid-solidification-processed (RSP) Al-2.6Li-1.0Cu-0.5Mg-0.5Zr (Allied 644-B) extrusions, has been studied, and results compared with data on an equivalent ingot-metallurgy (I/M) Al-Li alloy, 2090-T81 plate. Fatigue-crack growth resistance of the RSP Al-Li alloy is found to be comparable to the I/M Al-Li alloy; in contrast, crack velocities in MA 905-XL extrusions are nearly three orders of magnitude faster. Growth-rate response in both P/M Al-Li alloys, however, is high anisotropic. Results are interpreted in terms of the microstructural influence of strengthening mechanism, slip mode, grain morphology and texture on the development of crack-tip shielding from crack-path deflection and crack closure. 14 refs., 7 figs., 2 tabs.
Venkateswara Rao, K.T.; Ritchie, R.O. (Lawrence Berkeley Lab., CA (United States)); Kim, N.J. (Pohang Inst. of Science and Technology (Korea, Republic of)); Pizzo, P.P. (San Jose State Univ., CA (United States))
This progress report briefly summarizes the research performed under the referenced grant for the period from 1 December 1990 to 31 December 1991, and contains a cumulative listing of technical presentations and publications dating back to 1 June 1988. Under this grant, a multi-disciplinary research program is undertaken to address certain fundamental issues relating to corrosion fatigue crack growth in structurally important alloys in aqueous environments. The principal goal of the research is to develop and expand the scientific understanding of the processes that control corrosion fatigue crack growth, particularly for ferrous alloys in terms of the controlling mechanical and chemical/electrochemical processes and their interactions with the microstructure. Focus is placed upon the austenitic iron-chromium-nickel (FeCrNi) alloys because of the need to resolve certain mechanistic issues and because of extensive utilization of these alloys in the power generation and chemical industries. Emphasis is given to the growth of short (small) cracks at low growth rates because crack growth in this regime is expected to be more sensitive to changes in external chemical/electrochemical variables.
Metals removal from spent salts
A method and apparatus for removing metal contaminants from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents may be added to precipitate the metal oxide and/or the metal as either metal oxide, metal hydroxide, or as a salt. The precipitated materials are filtered, dried and packaged for disposal as waste or can be immobilized as ceramic pellets. More than about 90% of the metals and mineral residues (ashes) present are removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be spray-dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 1.0 ppm of contaminants.
Hsu, Peter C. (Pleasanton, CA); Von Holtz, Erica H. (Livermore, CA); Hipple, David L. (Livermore, CA); Summers, Leslie J. (Livermore, CA); Brummond, William A. (Livermore, CA); Adamson, Martyn G. (Danville, CA)
Metal to ceramic sealed joint
A metal to ceramic sealed joint which can withstand wide variations in temperature and maintain a good seal is provided for use in a device adapted to withstand thermal cycling from about 20 to about 1000 degrees C. The sealed joint includes a metal member, a ceramic member having an end portion, and an active metal braze forming a joint to seal the metal member to the ceramic member. The joint is positioned remote from the end portion of the ceramic member to avoid stresses at the ends or edges of the ceramic member. The sealed joint is particularly suited for use to form sealed metal to ceramic joints in a thermoelectric generator such as a sodium heat engine where a solid ceramic electrolyte is joined to metal parts in the system. 11 figures.
Lasecki, J.V.; Novak, R.F.; McBride, J.R.
A metal to ceramic sealed joint which can withstand wide variations in temperature and maintain a good seal is provided for use in a device adapted to withstand thermal cycling from about 20 to about 1000 degrees C. The sealed joint includes a metal member, a ceramic member having an end portion, and an active metal braze forming a joint to seal the metal member to the ceramic member. The joint is positioned remote from the end portion of the ceramic member to avoid stresses at the ends or edges of the ceramic member. The sealed joint is particularly suited for use to form sealed metal to ceramic joints in a thermoelectric generator such as a sodium heat engine where a solid ceramic electrolyte is joined to metal parts in the system.
Lasecki, John V. (Livonia, MI); Novak, Robert F. (Farmington Hills, MI); McBride, James R. (Ypsilanti, MI)
Corrosion-resistant metal surfaces
The present invention relates to metal surfaces having thereon an ultrathin (e.g., less than ten nanometer thickness) corrosion-resistant film, thereby rendering the metal surfaces corrosion-resistant. The corrosion-resistant film includes an at least partially crosslinked amido-functionalized silanol component in combination with rare-earth metal oxide nanoparticles. The invention also relates to methods for producing such corrosion-resistant films.
Sugama, Toshifumi (Wading River, NY)
Nonferrous Metal Melting -- Marketing Kit
The industrial sector increasingly relies on electric furnaces for nonferrous metal melting due to declining electricity cost, greater use of recycled secondary nonferrous materials, and tightened environmental regulations. This Nonferrous Metal Melting -- Marketing Kit is designed to help utility sales and marketing personnel perform a progressive analysis of electrotechnology applications in nonferrous metal melting systems. The kit is designed for utility personnel who have limited knowledge of the no...
Metal-ceramic joint assembly
A metal-ceramic joint assembly in which a brazing alloy is situated between metallic and ceramic members. The metallic member is either an aluminum-containing stainless steel, a high chromium-content ferritic stainless steel or an iron nickel alloy with a corrosion protection coating. The brazing alloy, in turn, is either an Au-based or Ni-based alloy with a brazing temperature in the range of 9500 to 1200.degree. C.
Li, Jian (New Milford, CT)
Method for preparing porous metal hydride compacts
A method for preparing porous metallic-matrix hydride compacts which can be repeatedly hydrided and dehydrided without disintegration. A mixture of a finely divided metal hydride and a finely divided matrix metal is contacted with a poison which prevents the metal hydride from dehydriding at room temperature and atmospheric pressure. The mixture of matrix metal and poisoned metal hydride is then compacted under pressure at room temperature to form porous metallic-matrix hydride compacts.
Ron, M.; Gruen, D.M.; Mendelsohn, M.H.; Sheft, I.
Metallic hydrogen research
Theoretical studies predict that molecular hydrogen can be converted to the metallic phase at very high density and pressure. These conditions were achieved by subjecting liquid hydrogen to isentropic compression in a magnetic-flux compression device. Hydrogen became electrically conducting at a density of about 1.06 g/cm/sup 3/ and a calculated pressure of about 2 Mbar. In the experimental device, a cylindrical liner, on implosion by high explosive, compresses a magnetic flux which in turn isentropically compresses a hydrogen sample; coaxial conical anvils prevent escape of the sample during compression. One anvil contains a coaxial cable that uses alumina ceramic as an insulator; this probe allows continuous measurement of the electrical conductivity of the hydrogen. A flash x-ray radiograph exposed during the experiment records the location of the sample-tube boundaries and permits calculation of the sample density. The theoretical underpinnings of the metallic transition of hydrogen are briefly summarized, and the experimental apparatus and technique, analytical methods, and results are described. 9 figures.
Burgess, T.J.; Hawke, R.S.
Metals Welded and Thickness Parameters
...more sheet metal stampings that do not require gas-tight or liquid-tight joints can be more economically joined by high-speed RSW than by
Primary Metals - Compressor Motors Failing
This power quality (PQ) case study presents the investigation of four failures of compressor motors for a two stage chiller at a primary metals manufacturing facility.
This patent deals with the soldering of aluminum to metals of different types, such as copper, brass, and iron. This is accomplished by heating the aluminum metal to be soldered to slightly above 30 deg C, rubbing a small amount of metallic gallium into the part of the surface to be soldered, whereby an aluminum--gallium alloy forms on the surface, and then heating the aluminum piece to the melting point of lead--tin soft solder, applying lead--tin soft solder to this alloyed surface, and combining the aluminum with the other metal to which it is to be soldered.
Erickson, G.F.
Fatigue Crack Growth Mechanisms in a Forged IN 718 Nickel-Based ...
Single-edged notched (SEN) specimens were machined from the plate using electro- discharge .... U. Glatzel and M. Feller-Kniepmeier: Scripta Metall. Mater.
Metal decontamination for waste minimization using liquid metal refining technology
The current Department of Energy Mixed Waste Treatment Project flowsheet indicates that no conventional technology, other than surface decontamination, exists for metal processing. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain concentration. This project is in support of the National Mixed Low Level Waste Treatment Program. Because of the high cost of disposal, it is important to develop an effective decontamination and volume reduction method for low-level contaminated metals. It is important to be able to decontaminate complex shapes where surfaces are hidden or inaccessible to surface decontamination processes and destruction of organic contamination. These goals can be achieved by adapting commercial metal refining processes to handle radioactive and organic contaminated metal. The radioactive components are concentrated in the slag, which is subsequently vitrified; hazardous organics are destroyed by the intense heat of the bath. The metal, after having been melted and purified, could be recycled for use within the DOE complex. In this project, we evaluated current state-of-the-art technologies for metal refining, with special reference to the removal of radioactive contaminants and the destruction of hazardous organics. This evaluation was based on literature reports, industrial experience, plant visits, thermodynamic calculations, and engineering aspects of the various processes. The key issues addressed included radioactive partitioning between the metal and slag phases, minimization of secondary wastes, operability of the process subject to widely varying feed chemistry, and the ability to seal the candidate process to prevent the release of hazardous species.
Joyce, E.L. Jr.; Lally, B. [Los Alamos National Lab., NM (United States); Ozturk, B.; Fruehan, R.J. [Carnegie-Mellon Univ., Pittsburgh, PA (United States). Dept. of Materials Science and Engineering
FATIGUE RESISTANT FIBERGLASS LAMINATES FOR WIND TURBINE BLADES (published for Wind Energy 1996, ASME, pp. 46-51)
FATIGUE RESISTANT FIBERGLASS LAMINATES FOR WIND TURBINE BLADES (published for Wind Energy 1996/MSU database to lifetime prediction as described in Ref. [1]. INTRODUCTION Most U.S. fiberglass wind turbine Turbine Blade Lifetime Predictions" Proc. 1996 ASME Wind Energy Symposium. (To be published) 2. J
Fatigue and failure responses of lead zirconate titanate multilayer actuator under unipolar high-field electric cycling
Lead zirconate titanate (PZT) multilayer actuators with an interdigital electrode design were studied under high electric fields (3 and 6 kV/mm) in a unipolar cycling mode. A 100 Hz sine wave was used in cycling. Five specimens tested under 6 kV/mm failed from 3.8 10^5 to 7 10^5 cycles, whereas three other specimens tested under 3 kV/mm were found to be still functional after 10^8 cycles. Variations in piezoelectric and dielectric responses of the tested specimens were observed during the fatigue test, depending on the measuring and cycling conditions. Selected fatigued and damaged actuators were characterized using an impedance analyzer or small signal measurement. A scanning acoustic microscope also was employed as a nondestructive tool to detect the presence of defects. Failed plates were subsequently sectioned, and the extensive cracks and porous regions were observed to be across the PZT layers. The results from this study have demonstrated that the high-field cycling can accelerate the fatigue of PZT stacks as long as the partial discharge is controlled. The small signal measurement can also be integrated into the large signal measurement to characterize the fatigue response of PZT stacks in a more comprehensive basis. The former can further serve as an experimental method to monitor the behavior of PZT stacks.
Zeng, Fan W [ORNL; Wang, Hong [ORNL; Lin, Hua-Tay [ORNL
A numerical method for predicting the bending fatigue life of NiTi and stainless steel root canal
or fluctuating strains at nominal stresses below (and often much less than) the yield strength of the material (Bannantine et al. 1989, ASM Interna- tional 1996). The material will succumb to propagat- ing fatiguecracks) and are subjected to harsh working (corrosive) condi- tions under a combination of torsional and bending moments
Zheng, Yufeng
Two-dimensional finite element simulation of fracture and fatigue behaviours of alumina microstructures for hip prosthesis
, finite element, fatigue, fracture, ceramic, microstructure * Corresponding author. Email address: email@example.com #12;2 1. Introduction Alumina is known as a primary ceramic material in biomedical industry. Particularly, Al2O3 is widely used as the material of a femoral head and an acetabular cup of hip
Paris-Sud XI, Université de
An improved method for extracting uranium from aqueous solutions by solvent extraction is presented. A difficulty encountered in solvent extraction operations using an organic extractant (e.g., tributyl phosphate dissolved in kerosene or carbon tetrachloride) is that emulsions sometimes form, and phase separation is difficult or impossible. This difficulty is overcome by dissolving the organic extractant in a molten wax which is a solid at operating temperatures. After cooling, the wax which now contains the extractant, is broken into small particles (preferably flakes) and this wax complex'' is used to contact the uranium bearing solutions and extract the metal therefrom. Microcrystalline petroleum wax and certain ethylene polymers have been found suitable for this purpose.
Lewis, G.W. Jr.; Rhodes, D.E.
Physical Properties of Metals
Table 1 Some physical properties of metals at room temperature...0.176 �?� �?� �?� Tantalum 16.6 0.1391 6.5 54.4 135.0 Technetium 11.5 �?� 7.05 50.2 185.0 Tellurium 6.237 0.201 18.2 5.98�??6.02 1�??50 Terbium 8.230 0.1818 10.3 11.1 1150 Thallium 11.872 0.130 28 47 150 Thorium 11.8 0.11308 10.9 77 157 Thulium 9.321 0.1598 13.3 16.9 676 Tin 5.765 0.205 21 62.8 110 Titanium 4.507...
Creating bulk nanocrystalline metal.
Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.
Fredenburg, D. Anthony (Georgia Institute of Technology, Atlanta, GA); Saldana, Christopher J. (Purdue University, West Lafayette, IN); Gill, David D.; Hall, Aaron Christopher; Roemer, Timothy John (Ktech Corporation, Albuquerque, NM); Vogler, Tracy John; Yang, Pin
Liquid metal thermoacoustic engine
We are studying a liquid metal thermoacoustic engine both theoretically and experimentally. This type of engine promises to produce large quantities of electrical energy from heat at modest efficiency with no moving parts. A sound wave is usually thought of as consisting of pressure oscillations, but always attendant to the pressure oscillation are temperature oscillations. The combination produces a rich variety of ''thermoacoustic'' effects. These effects are usually so small that they are never noticed in everyday life; nevertheless under the right circumstances they can be harnessed to produce powerful heat engines, heat pumps, and refrigerators. In our liquid metal thermoacoustic engine, heat flow from a high temperature source to a low temperature sink generates a high-amplitude standing acoustic wave in liquid sodium. This acoustic power is converted to electric power by a simple magnetohydrodynamic effect at the acoustic oscillation frequency. We have developed a detailed thermoacoustic theory applicable to this engine, and find that a reasonably designed liquid sodium engine operating between 700/sup 0/C and 100/sup 0/C should generate about 60 W/cm/sup 2/ of acoustic power at about 1/3 of Carnot's efficiency. Construction of a 3000 W-thermal laboratory model engine has just been completed, and we have exciting preliminary experimental results as of the time of preparation of this manuscript showing, basically, that the engine works. We have also designed and built a 1 kHz liquid sodium magnetohydrodynamic generator and have extensive measurements on it. It is now very well characterized both experimentally and theoretically. The first generator of its kind, it already converts acoustic power to electric power with 40% efficiency. 16 refs., 5 figs.
Swift, G.W.; Migliori, A.; Wheatley, J.C.
Nanostructured metal-polyaniline composites
Metal-polyaniline (PANI) composites are provided together with a process of preparing such composites by an electrodeless process. The metal of the composite can have nanoscale structural features and the composites can be used in applications such as catalysis for hydrogenation reactions and for analytical detection methods employing SERS.
Wang, Hsing-Lin (Los Alamos, NM); Li, Wenguang (Elgin, IL); Bailey, James A. (Los Alamos, NM); Gao, Yuan (Brewer, ME)
Metal recovery from porous materials
The present invention relates to recovery of metals. More specifically, the present invention relates to the recovery of plutonium and other metals from porous materials using microwaves. The United States Government has rights in this invention pursuant to Contract No. DE-AC09-89SR18035 between the US Department of Energy and Westinghouse Savannah River Company.
Sturcken, E.F.
Reversible Bending Fatigue Test System for Investigating Vibration Integrity of Spent Nuclear Fuel during Transportation
Transportation packages for spent nuclear fuel (SNF) must meet safety requirements under normal and accident conditions as specified by federal regulations. During transportation, SNF experiences unique conditions and challenges to cladding integrity due to the vibrational and impact loading during road or rail shipment. Oak Ridge National Laboratory (ORNL) has been developing testing capabilities that can be used to improve the understanding of the impacts on SNF integrity due to vibration loading, especially for high burn-up SNF in normal transportation operation conditions. This information can be used to meet the nuclear industry and U.S. Nuclear Regulatory Commission needs in the area of safety and security of spent nuclear fuel storage and transport operations. The ORNL developed test system can perform reversible-bending fatigue testing to evaluate both the static and dynamic mechanical response of SNF rods under simulated loads. The testing apparatus is also designed to meet the challenges of hot-cell operation, including remote installation and detachment of the SNF test specimen, in-situ test specimen deformation measurement, and implementation of a driving system suitable for use in a hot cell. The system contains a U-frame set-up equipped with uniquely designed grip rigs, to protect SNF rod and to ensure valid test results, and use of 3 specially designed LVDTs to obtain the in-situ curvature measurement. A variety of surrogate test rods have been used to develop and calibrate the test system as well as in performing a series of systematic cyclic fatigue tests. The surrogate rods include stainless steel (SS) cladding, SS cladding with cast epoxy, and SS cladding with alumina pellets inserts simulating fuel pellets. Testing to date has shown that the interface bonding between the SS cladding and the alumina pellets has a significant impact on the bending response of the test rods as well as their fatigue strength. The failure behaviors observed from tested surrogate rods provides a fundamental understanding of the underlying failure mechanisms of the SNF surrogate rod under vibration which has not been achieved previously. The newly developed device is scheduled to be installed in the hot-cell in summer 2013 to test high burnup SNF.
Wang, Jy-An John [ORNL; Wang, Hong [ORNL; Bevard, Bruce Balkcom [ORNL; Howard, Rob L [ORNL; Flanagan, Michelle [U.S. Nuclear Regulatory Commission
Recipient: 1997 LMD Light Metals Technical Service Award
TMS Logo. Recipient: 1997 LMD Light Metals Technical Service Award. The Minerals, Metals & Materials Society's Light Metals Division Light Metals Technical�...
On the Role of Pieirls Stress in the Shock Response of Cubic Metals
Effects of Microstructural and Mechanical Length Scales on Fatigue Crack ... Components and Mechanical Properties of an Acicular Ferrite Pipeline Steel.
Casimir Repulsion between Metallic Objects in Vacuum
We give an example of a geometry in which two metallic objects in vacuum experience a repulsive Casimir force. The geometry consists of an elongated metal particle centered above a metal plate with a hole. We prove that ...
Levin, Michael
Method for controlled hydrogen charging of metals
A method for controlling hydrogen charging of hydride forming metals through a window of a superimposed layer of a non-hydriding metal overlying the portion of the hydride forming metals to be charged.
Cheng, Bo-Ching (Fremont, CA); Adamson, Ronald B. (Fremont, CA)
User`s guide for the frequency domain algorithms in the LIFE2 fatigue analysis code
The LIFE2 computer code is a fatigue/fracture analysis code that is specialized to the analysis of wind turbine components. The numerical formulation of the code uses a series of cycle count matrices to describe the cyclic stress states imposed upon the turbine. However, many structural analysis techniques yield frequency-domain stress spectra and a large body of experimental loads (stress) data is reported in the frequency domain. To permit the analysis of this class of data, a Fourier analysis is used to transform a frequency-domain spectrum to an equivalent time series suitable for rainflow counting by other modules in the code. This paper describes the algorithms incorporated into the code and their numerical implementation. Example problems are used to illustrate typical inputs and outputs.
Sutherland, H.J. [Sandia National Labs., Albuquerque, NM (United States); Linker, R.L. [New Mexico Engineering Research Inst., Albuquerque, NM (United States)
Assessing Fatigue and Ultimate Load Uncertainty in Floating Offshore Wind Turbines Due to Varying Simulation Length
With the push towards siting wind turbines farther offshore due to higher wind quality and less visibility, floating offshore wind turbines, which can be located in deep water, are becoming an economically attractive option. The International Electrotechnical Commission's (IEC) 61400-3 design standard covers fixed-bottom offshore wind turbines, but there are a number of new research questions that need to be answered to modify these standards so that they are applicable to floating wind turbines. One issue is the appropriate simulation length needed for floating turbines. This paper will discuss the results from a study assessing the impact of simulation length on the ultimate and fatigue loads of the structure, and will address uncertainties associated with changing the simulation length for the analyzed floating platform. Recommendations of required simulation length based on load uncertainty will be made and compared to current simulation length requirements.
Stewart, G.; Lackner, M.; Haid, L.; Matha, D.; Jonkman, J.; Robertson, A.
On the micromechanisms of fatigue-crack propagation in aluminum- lithium alloys: Sheet vs. plate material
Micromechanisms influencing the propagation of long (>10 mm) fatigue cracks in aluminum-lithium alloys are examined by specifically comparing crack-growth kinetics in a peak-aged Al-Li-Cu-Zr alloy 2090, processed as 1.6-mm thin (T83) sheet and 12.7-mm thick (T81) plate. It is found that in general crack-growth rates are significantly faster in the sheet material at equivalent stress-intensity levels, due to differences in the role of crack-tip shielding, resulting from crack deflection and consequent crack closure from wedging of fracture-surface asperities. Microstructurally, such differences are related to variations in the degree of recrystallization, grain structure and deformation texture in the two wrought-product forms. 14 refs., 4 figs.
Rao Venkateswara, K.T.; Ritchie, R.O. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering); Bucci, R.J. (Aluminum Co. of America, Alcoa Center, PA (United States). Alcoa Labs.)
Frequency-domain stress prediction algorithm for the LIFE2 fatigue analysis code
The LIFE2 computer code is a fatigue/fracture analysis code that is specialized to the analysis of wind turbine components. The numerical formulation of the code uses a series of cycle mount matrices to describe the cyclic stress states imposed upon the turbine. However, many structural analysis techniques yield frequency-domain stress spectra and a large body of experimental loads (stress) data is reported in the frequency domain. To permit the analysis of this class of data, a Fourier analysis module has been added to the code. The module transforms the frequency spectrum to an equivalent time series suitable for rainflow counting by other modules in the code. This paper describes the algorithms incorporated into the code and uses experimental data to illustrate their use. 10 refs., 11 figs.
Method of coating metal surfaces to form protective metal coating thereon
A process is disclosed for forming a protective metal coating on a metal surface using a flux consisting of an alkali metal fluoride, an alkaline earth metal fluoride, an alkali metal fluoaluminate, an alkali metal fluosilicate, and mixtures thereof. The flux, in particulate form, is mixed with particles of a metal coating material which may comprise aluminum, chromium, mixtures thereof, and alloys containing at least 50 wt. % aluminum and the particulate mixture is applied to the metal surface in a single step, followed by heating the coated metal surface to a temperature sufficient to cause the metal coating material to react with the metal surface to form a protective reaction product in the form of a metal coating bonded to the metal surface. The metal surface which reacts with the metal coating material to form the protective coating may comprise Fe, Co, Ni, Ti, V, Cr, Mn, Zr, Nb, Mo, Tc, Hf, Ta, W, Re and alloys thereof.
Krikorian, Oscar H. (Danville, CA); Curtis, Paul G. (Tracy, CA)
A process is disclosed for forming a protective metal coating on a metal surface using a flux consisting of an alkali metal fluoride, an alkaline earth metal fluoride, an alkali metal fluoaluminate, an alkali metal fluosilicate, and mixtures thereof. The flux, in particulate form, is mixed with particles of a metal coating material which may comprise aluminum, chromium, mixtures thereof, and alloys containing at least 50 wt. % aluminum and the particulate mixture is applied to the metal surface in a single step, followed by heating the coated metal surface to a temperature sufficient to cause the metal coating material to react with the metal surface to form a protective reaction product in the form of a metal coating bonded to the metal surface. The metal surface which reacts with the metal coating material to form the protective coating may comprise Fe, Co, Ni, Ti, V, Cr, Mn, Zr, Nb, Mo, Tc, Hf, Ta, W, Re and alloys thereof. 1 figure.
Krikorian, O.H.; Curtis, P.G.
Testing Controls to Mitigate Fatigue Loads in the Controls Advanced Research Turbine
Wind turbines are complex, nonlinear, dynamic systems forced by aerodynamic, gravitational, centrifugal, and gyroscopic loads. The aerodynamics of wind turbines is nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated three-dimensional (3D) turbulent wind inflow field with imbedded coherent vortices that drive fatigue loads and reduce lifetime. Design of control algorithms for wind turbines must account for multiple control objectives. Future large multi-megawatt turbines must be designed with lighter weight structures, using active controls to mitigate fatigue loads, maximize energy capture, and add active damping to maintain stability for these dynamically active structures operating in a complex environment. Researchers at the National Renewable Energy Laboratory are designing, implementing, and testing advanced controls to maximize energy extraction and reduce structural dynamic loads. These control designs are based on a linear model of the turbine that is generated by specialized modeling software. This paper describes testing of a control algorithm to mitigate blade, tower, and drivetrain loads using advanced state-space control methods. The controller uses independent blade pitch to regulate the turbine's speed in Region 3, mitigate the effects of shear across the rotor disk, and add active damping to the tower's first fore-aft bending mode. Additionally, a separate generator torque control loop is designed to add active damping to the tower's first side-side mode and the first drivetraintorsion mode. This paper discusses preliminary implementation and field tests of this controller in the Controls Advanced Research Turbine at the National Renewable Energy Laboratory. Also included are preliminary comparisons of the performance of this controller to results from a typical baseline Proportional-Integral-Derivative controller designed with just Region 3 speed regulation as the goal.
Wright, A. D.; Fingersh, L. J.; Stol, K. A.
Low cycle thermal fatigue testing of beryllium grades for ITER plasma facing components
A novel technique has been used to test the relative low cycle thermal fatigue resistance of different grades of US and Russian beryllium, which is proposed as plasma facing armor for fusion reactor first wall, limiter, and divertor components. The 30 kW electron beam test system at Sandia National Laboratories was used to sweep the beam spot along one direction at 1 Hz. This produces a localized temperature ``spike`` of 750{degree}C for each pass of the beam. Large thermal stresses in excess of the yield strength are generated due to very high spot heat flux, 250 MW/m{sup 2}. Cyclic plastic strains on the order of 0.6% produced visible cracking on the heated surface in less than 3000 cycles. An in-vacuo fiber optic borescope was used to visually inspect the beryllium surfaces for crack initiation. Grades of US beryllium tested included: S-65C, S- 65H, S-200F, S-200F-H, SR-200, I-400, extruded high purity, HIP`d spherical powder, porous beryllium (94% and 98% dense), Be/30% BeO, Be/60% BeO, and TiBe{sub 12}. Russian grades included: TGP-56, TShGT, DShG-200, and TShG-56. Both the number of cycles to crack initiation, and the depth of crack propagation, were measured. The most fatigue resistant grades were S-65C, DShG-200, TShGT, and TShG-56. Rolled sheet Be (SR-200) showed excellent crack propagation resistance in the plane of rolling, despite early formation of delamination cracks. Only one sample showed no evidence of surface melting, Extruded (T). Metallographic and chemical analyses are provided. Good agreement was found between the measured depth of cracks and a 2-D elastic-plastic finite element stress analysis.
Watson, R.D.; Youchison, D.L. [Sandia National Labs., Livermore, CA (United States); Dombrowski, D.E. [Brush Wellman, Inc., Cleveland, OH (United States); Guiniatouline, R.N. [Efremov Institute, (Russia); Kupriynov, I.B. [Russian Institute of Inorganic Materials (Russia)
An analysis of muscle fatigue due to complex tasks and its relation to the strain index
The Strain Index was originally designed to analyze mono-task jobs. An experiment using a grip dynamometer was used to simulate six multiple task jobs to study the effect of complex tasks on localized muscle fatigue and to evaluate six different models used to calcula te a Complex Strain Index score. These models included average Strain Index score, unadjusted summation, duration adjusted summation, complex equation, minimum intensity, and peak intensity. Two methods of calculating a continuous Strain Index score were also analyzed. Ratings of perceived exertion, hand and forearm fatigue and discomfort, Difficulty Rating, maximum voluntary contraction (MVC), and percent strength loss were recorded for each of the six treatments. Electromyography (EMG) was also recorded for the 24 subjects (12 males and females) who completed the experiment. The EMG signal was analyzed using root mean square (RMS), initial mean power frequency (IMnPF), and slope of the mean power frequency (MnPF). Each treatment, lasting one hour each, contained a primary exertion (Task 1) of either 10% or 40% MVC for three seconds and a secondary exertion (Task 2) of either 10% or 40% MVC for one or three seconds. Subjective variables linearly increased (R2 > 0.88) over the duration of the treatments and significantly differed between treatments (p 0.05). A significant difference was found for MnPF slope pre and post treatment, but no treatment effect was found (p > 0.05). The complex equation method of calculating a Strain Index score was the only model of the six evaluated that met all criteria for being an acceptable method of calculating a Complex Strain Index score. The two continuous methods presented for calculating a Strain Index score should not be used for job analysis until further research evaluates their reliability, validity, and critical scores for Hazard Classification.
Stephens, John-Paul
Design criteria and mitigation options for thermal fatigue effects in ATW blankets.
Thermal fatigue due to beam interruptions is an issue that must be addressed in the design of an ATW blanket. Two different approaches can be taken to address this issue. One approach is to analyze current ATW blanket designs in order to set interrupt frequency design limits for the accelerator. The other approach is to assume that accelerator reliability can not be guaranteed before design and construction of the blanket. In this approach the blanket must be designed so as to accommodate an accelerator with a beam interruption frequency significantly higher than current high power accelerators in order to provide a margin of error. Both approaches are considered in this paper. Both a sodium cooled blanket design and a lead-bismuth cooled blanket design are considered. Thermal hydraulic analysis of the blanket for beam interruption transients is carried out with the SASSYS-1 systems analysis code to obtain the time histories of the coolant temperatures in contact with structural components. These coolant temperatures are then used in a detailed structure temperature calculation to obtain structure surface and structure average temperatures. The difference between the average temperature and the surface temperature is used to obtain thermal strains. Low cycle fatigue curves from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code are used to determine the number of cycles that the structural components can endure, based on these strains. Calculations are made for base case designs and for a number of mitigation options. The mitigation options include using two separate accelerators to provide the beam, reducing the thickness of the above core load pads in the subassemblies, increasing the coolant flow rate or reducing power in order to reduce the core temperature rise, and reducing the superheat in the once-through steam generator.
Dunn, F. E.
An apparatus is described for preparing high purity metal such as uranium, plutonium and the like from an impure mass of the same metal. The apparatus is arranged so that the impure metal is heated and swept by a stream of hydrogen gas bearing a halogen such as iodine. The volatiie metal halide formed is carried on to a hot filament where the metal halide is decomposed and the molten high purity metal is collected in a rceeiver below
Catalysis using hydrous metal oxide ion exchangers
In a process which is catalyzed by a catalyst comprising an active metal on a carrier, said metal being active as a catalyst for the process, an improvement is provided wherein the catalyst is a hydrous, alkali metal or alkaline earth metal titanate, zirconate, niobate or tantalate wherein alkali or alkaline earth metal cations have been exchanged with a catalytically effective amount of cations of said metal.
Dosch, R.G.; Stephens, H.P.; Stohl, F.V.
Catalysis using hydrous metal oxide ion exchanges
Dosch, Robert G. (Albuquerque, NM); Stephens, Howard P. (Albuquerque, NM); Stohl, Frances V. (Albuquerque, NM)
One Scientific Communtiy Focused on Nanoscience Integration | Center for
NLE Websites -- All DOE Office Websites
The 2013 Fall Call for Proposals has closed. Notifications will be sent out in December. The 2013 Fall Call for Proposals has closed. Notifications will be sent out in December. The next call for proposals will be announced March 1, 2014. The database is currently open for Rapid Access Proposals. These should be limited in scope and have strong justification for expedited processing. If you have recently been to CINT to work on your project, or are just finishing a project, please complete our CINT User Satisfaction Survey. Science Highlight: Strong coupling in the sub-wavelength limit using metamaterial nanocavities Scientific Achievement - We demonstrate that the strong light-matter coupling between a metamaterial and an intersubband transition in semiconductor heterostructures is fully scalable from the mid-infrared (~10 microns) to the near-infrared (~1.5 microns) and happens on a single nanocavity level in deep sub-wavelength volumes.
X-rays and Neutrons: Essential Tools for Nanoscience Research
on Nanoscale Science, Engineering and Technology (NSET) and the National Nanotechnology Initiative (NNI). Go To Top Summary Virtually all of the grand challenges in...
Applications of Raman Microscopy to Nanoscience Workshop, October...
graphene) that I work on." Some overall comments and observations: 1) Registration capacity was achieved quickly; the limit of 80 people was determined by the room size, and...
Charge transport in molecular devices. Nanoscience and nanotechologies: new science?
resolution the electronic energy level of atoms and molecules and also determine the structure i. The technology of thin films is nowadays widely used in particular in the electronic industry. This science has nanoparticles can have mechanical properties comparable with the hardest stainless steel while normal nickel
Qian, Ning
Sandia National Labs: PCNSC: Departments: Radiation and Nanosciences
Home About Us Departments Radiation, Nano Materials, & Interface Sciences > Radiation & Solid Interactions > Nanomaterials Sciences > Surface & Interface Sciences Semiconductor &...
Engineering Metal Impurities in Multicrystalline Silicon Solar...
Engineering Metal Impurities in Multicrystalline Silicon Solar Cells Print Transition metals are one of the main culprits in degrading the efficiency of multicrystalline solar...
Metals Thin-Films Information at NIST
NIST Home > Metals Thin-Films Information at NIST. Metals Thin-Films Information at NIST. (the links below are a compilation ...
Industrial Ecology and Metal Production - TMS
Jul 2, 2008 ... Topic Title: Powerpoint: Industrial Ecology and Metal Production Topic Summary: Metal extraction is on the the most Earth-intrusive industrial�...
Metallic Inclusions in Uranium Dioxide", LBL-11117 (1980).in Hypostoichiornetric Uranium Dioxide 11 , LBL-11095 (OF METALLIC INCLUSIONS IN URANIUM DIOXIDE Rosa L. Yang and
Yang, Rosa L.
Bulk Metallic Glasses VIII - Programmaster.org
Aug 2, 2010 ... Sponsorship, The Minerals, Metals and Materials Society .... The Oxidation Behavior of an FeCo-Based Bulk Metallic Glass at 600 - 700C.
Molten Metal Safety Approach through a Network
Abstract Scope, Molten Metal explosion or splash is a major risk encountered in the ... In-Line Salt-ACD: A Chlorine�Free Technology for Metal Treatment.
Recycling Metals Using the MOCVD Process
Aug 1, 2000 ... Secondly, the volatile metal organic compound is purified by fractional distillation. Thirdly, the purified metal organic compound is decomposed�...
About Rare Earth Metals | Ames Laboratory
About Rare Earth Metals About Rare Earth Metals What Are Rare Earths? Ames Laboratory's Materials Preparation Center The Ames Process for Purification of Rare...
Quinary metallic glass alloys
At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf).sub.a (Al,Zn).sub.b (Ti,Nb).sub.c (Cu.sub.x Fe.sub.y (Ni,Co).sub.z).sub.d wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 to 7.5 atomic percent, d comprises the balance, d.multidot.y is less than 10 atomic percent, and x/z ranges from 0.5 to 2.
Lin, Xianghong (Pasadena, CA); Johnson, William L. (Pasadena, CA)
At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10{sup 3}K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf){sub a}(Al,Zn){sub b}(Ti,Nb){sub c}(Cu{sub x}Fe{sub y}(Ni,Co){sub z}){sub d} wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 to 7.5 atomic percent, d comprises the balance, d{hor_ellipsis}y is less than 10 atomic percent, and x/z ranges from 0.5 to 2.
Lin, X.; Johnson, W.L.
Contributions to an Improved Oxygen and Thermal Transport Model and Development of Fatigue Analysis Software for Asphalt Pavements
Fatigue cracking is one primary distress in asphalt pavements, dominant especially in later years of service. Prediction of mixture fatigue resistance is critical for various applications, e.g., pavement design and preventative maintenance. The goal of this work was to develop a tool for prediction of binder aging level and mixture fatigue life in pavement from unaged binder/mixture properties. To fulfill this goal, binder oxidation during the early fast-rate period must be understood. In addition, a better hourly air temperature model is required to provide accurate input for the pavement temperature prediction model. Furthermore, a user-friendly software needs to be developed to incorporate these findings. Experiments were conducted to study the carbonyl group formation in one unmodified binder (SEM 64-22) and one polymer-modified binder (SEM 70-22), aged at five elevated temperatures. Data of SEM 64-22, especially at low temperatures, showed support for a parallel-reaction model, one first order reaction and one zero order reaction. The model did not fit data of SEM 70-22. The polymer modification of SEM 70-22 might be responsible for this discrepancy. Nonetheless, more data are required to draw a conclusion. Binder oxidation rate is highly temperature dependent. Hourly air temperature data are required as input for the pavement temperature prediction model. Herein a new pattern-based air temperature model was developed to estimate hourly data from daily data. The pattern is obtained from time series analysis of measured data. The new model yields consistently better results than the conventional sinusoidal model. The pavement aging and fatigue analysis (PAFA) software developed herein synthesizes new findings from this work and constant-rate binder oxidation and hardening kinetics and calibrated mechanistic approach with surface energy (CMSE) fatigue analysis algorithm from literature. Input data include reaction kinetics parameters, mixture test results, and pavement temperature. Carbonyl area growth, dynamic shear rheometer (DSR) function hardening, and mixture fatigue life decline are predicted as function of time. Results are plotted and saved in spreadsheets.
Jin, Xin
Materials Reliability Program: Second International Conference on Fatigue of Reactor Components (MRP-84): July 29-August 1, 2002; Sn owbird Ski and Conference Center, Snowbird, Utah
This proceedings contains information presented at the Second International Conference on Fatigue of Reactor Components held 31 July - 1 August, 2002 in Snowbird, Utah. This second conference, again sponsored by EPRI, the Organisation for Economic Co-operation and Development (OECD), the Nuclear Energy Agency/Committee on the Safety of Nuclear Installations (NEA/CSNI), and the U.S. Nuclear Regulatory Commission (NRC), provided a forum for the technical discussion of fatigue issues that affect the integri...
AISI/DOE Technology Roadmap Program: Characterization of Fatigue and Crash Performance of New Generation High Strength Steels for Automotive Applications
A 2-year project (2001-2002) to generate fatigue and high strain data for a new generation of high strength steels (HSS) has been completed in December 2002. The project tested eleven steel grades, including Dual Phase (DP) steels, Transformation-Induced Plasticity (TRIP) steels, Bake Hardenable (BH) steels, and conventional High Strength Low Alloy (HSLA) steels. All of these steels are of great interest in automotive industry due to the potential benefit in weight reduction, improved fuel economy, enhanced crash energy management and total system cost savings. Fatigue behavior includes strain controlled fatigue data notch sensitivity for high strength steels. High strain rate behavior includes stress-strain data for strain rates from 0.001/s to 1000/s, which are considered the important strain rate ranges for crash event. The steels were tested in two phases, seven were tested in Phase 1 and the remaining steels were tested in Phase. In a addition to the fatigue data and high st rain rate data generated for the steels studied in the project, analyses of the testing results revealed that Advanced High Strength Steels (AHSS) exhibit significantly higher fatigue strength and crash energy absorption capability than conventional HSS. TRIP steels exhibit exceptionally better fatigue strength than steels of similar tensile strength but different microstructure, for conditions both with or without notches present
Brenda Yan; Dennis Urban
Review of elastic stress and fatigue-to-failure data for branch connections and tees in relation to ASME design criteria for nuclear power piping systems
This is the third in a series of reports on the state-of-the art design guidance for piping system branch connections and tees provided by Section III of the ASME Boiler and Pressure Vessel Code. The other reports covered primary or limit-loads and nozzle flexibility. The principal objective of this report, as with the others, was to identify and collect the pertinent literature on the the subject and to identify needed improvements in the design methods and criteria of the Code based on the evaluation of the available information. This report does not propose changes in the design procedure of the Code. This report discusses the evaluation of stresses in branch connections and tees, correlation of these stresses with fatigue failures, and the Code rules for protection against fatigue failure in design applications. Because of the extensive amount of available information, the report was divided into two parts. Part I discusses cyclic internal pressure loading and Part II discusses moment loadings for the branch and run. The cyclic pressure loading fatigue parameters are mostly based on leakage, whereas, if the parameters were based on crack initiation, different and possibly higher valves would be developed. The fatigue evaluation procedure, which attempts to relate fatigue strength of piping components to strain-controlled, polished bar, and fatigue data appears to be inaccurate on the conservative side for high amplitude cycles and inaccurate on the unconservative side for low amplitude cycles. The report proposes additional analytical and experimental work.
Rodabaugh, E.C.; Moore, S.E.; Gwaltney, R.C.
Nanostructured Metal Oxide Anodes (Presentation)
This summarizes NREL's FY09 battery materials research activity in developing metal oxide nanostructured anodes to enable high-energy, durable and affordable li-ion batteries for HEVs and PHEVs.
Dillon, A. C.; Riley, L. A.; Lee, S.-H.; Kim, Y.-H.; Ban, C.; Gillaspie, D. T.; Pesaran, A.
Metal and Polymer Matrix Composites
Aluminum-fly Ash Composites Produced by Powder Metallurgy Processing � Characterisation of Al-AC8H/Al2O3p Metal Matrix Composites Produced by Stir�...
The Influence of Inclusions on Low Cycle Fatigue Life in a P/M ...
heat treated forgings at 204' C and 649� C at two stress levels. .... was evacuated over 24 hours using a diffusion pump system ..... evolving for fracture critical powder metal components by incor- porating Probabilistic Fracture Mechanics (
Liquid metal compositions containing a solid uranium compound dispersed therein is described. Uranium combines with tin to form the intermetallic compound USn/sub 3/. It has been found that this compound may be incorporated into a liquid bath containing bismuth and lead-bismuth components, if a relatively small percentage of tin is also included in the bath. The composition has a low thermal neutron cross section which makes it suitable for use in a liquid metal fueled nuclear reactor.
Teitel, R.J.
A process is given for anodically treating the surface of uranium articles, prior to metal plating. The metal is electrolyzed in an aqueous solution of about 10% polycarboxylic acid, preferably oxalic acid, from 1 to 5% by weight of glycerine and from 1 to 5% by weight of hydrochloric acid at from 20 to 75 deg C for from 30 seconds to 15 minutes. A current density of from 60 to 100 amperes per square foot is used.
Wehrmann, R.F.
High-Pressure Thermodynamic Properties of f-electron Metals, Transition Metal Oxides, and Half-Metallic Magnets
This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (1) Mott transitions in transition metal oxides, (2) magnetism in half-metallic compounds, and (3) large volume-collapse transitions in f-band metals.
Scalettar, Richard T.; Pickett, Warren E.
This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (i) Mott transitions in transition metal oxides, (ii) magnetism in half-metallic compounds, and (iii) large volume-collapse transitions in f-band metals.
Richard T. Scalettar; Warren E. Pickett
Metal detector technology data base
The tests described in this report were conducted to obtain information on the effects target characteristics have on portal type metal detector response. A second purpose of the tests was to determine the effect of detector type and settings on the detection of the targets. Although in some cases comparison performance of different types and makes of metal detectors is found herein, that is not the primary purpose of the report. Further, because of the many variables that affect metal detector performance, the information presented can be used only in a general way. The results of these tests can show general trends in metal detection, but do little for making accurate predictions as to metal detector response to a target with a complex shape such as a handgun. The shape of an object and its specific metal content (both type and treatment) can have a significant influence on detection. Thus it should not be surprising that levels of detection for a small 100g stainless steel handgun are considerably different than for detection of the 100g stainless steel right circular cylinder that was used in these tests. 7 figs., 1 tab.
Porter, L.K.; Gallo, L.R.; Murray, D.W.
Experimental Study on Shear Fatigue Behavior and Stiffness Performance of Warm Mix Asphalt by adding Synthetic Wax
Synthetic waxes produced by standard and registered processes may be used to manufacture Warm Mix Asphalt (WMA), which is a modified asphalt concrete produced, applied and compacted at temperatures below those typically required. This feature leads to environmental benefits, such as reduced energy consumption, gas and fume emissions, as well as to economic/operational advantages, such as lower production costs and greater hauling distances for extended construction seasons with tighter schedules. The present article serves to compare the mechanical performance of a WMA produced by adding synthetic wax with a traditional Hot Mix Asphalt (HMA) specimen, in terms of shear fatigue response and both complex and stiffness moduli. The experimental results and related modeling work demonstrate that adding synthetic wax into the WMA composition does not hinder either the destructive or non-destructive performance of an HMA, and this finding is corroborated by respectively measuring fatigue life and stiffness.
Christophe Petit; Anne Millien; Francesco Canestrari; Valter Pannunzio; Amadeo Virgili
Theory manual for FAROW version 1.1: A numerical analysis of the Fatigue And Reliability Of Wind turbine components
Because the fatigue lifetime of wind turbine components depends on several factors that are highly variable, a numerical analysis tool called FAROW has been created to cast the problem of component fatigue life in a probabilistic framework. The probabilistic analysis is accomplished using methods of structural reliability (FORM/SORM). While the workings of the FAROW software package are defined in the user's manual, this theory manual outlines the mathematical basis. A deterministic solution for the time to failure is made possible by assuming analytical forms for the basic inputs of wind speed, stress response, and material resistance. Each parameter of the assumed forms for the inputs can be defined to be a random variable. The analytical framework is described and the solution for time to failure is derived.
Metal Detectives: New Book Details Titanic Investigation
Metal Detectives: New Book Details Titanic Investigation. For Immediate Release: April 15, 2008. ...
Metal salt catalysts for enhancing hydrogen spillover
A composition for hydrogen storage includes a receptor, a hydrogen dissociating metal doped on the receptor, and a metal salt doped on the receptor. The hydrogen dissociating metal is configured to spill over hydrogen to the receptor, and the metal salt is configured to increase a rate of the spill over of the hydrogen to the receptor.
Yang, Ralph T; Wang, Yuhe
Textured Metal Catalysts for Heterogeneous Catalysis ...
Biomass and Biofuels Advanced Materials Textured Metal Catalysts for Heterogeneous Catalysis Pacific Northwest National Laboratory. Contact ...
Stabilization of Nickel Metal Catalysts for Aqueous ...
Biomass and Biofuels Stabilization of Nickel Metal Catalysts for Aqueous Processing Systems Pacific Northwest National Laboratory.
Dispersion enhanced metal/zeolite catalysts
Dispersion stabilized zeolite supported metal catalysts are provided as bimetallic catalyst combinations. The catalyst metal is in a reduced zero valent form while the dispersion stabilizer metal is in an unreduced ionic form. Representative catalysts are prepared from platinum or nickel as the catalyst metal and iron or chromium dispersion stabilizer.
Sachtler, Wolfgang M. H. (Evanston, IL); Tzou, Ming-Shin (Evanston, IL); Jiang, Hui-Jong (Evanston, IL)
Horizontal electromagnetic casting of thin metal sheets
Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.
Hull, John R. (Hinsdale, IL); Lari, Robert J. (Aurora, IL); Praeg, Walter F. (Palos Park, IL); Turner, Larry R. (Naperville, IL)
Anaerobic microbial remobilization of coprecipitated metals
A process is provided for solubilizing coprecipitated metals. Metals in waste streams are concentrated by treatment with an iron oxide coprecipitating agent. The coprecipitated metals are solubilized by contacting the coprecipitate with a bacterial culture of a Clostridium species ATCC 53464. The remobilized metals can then be recovered and recycled. 4 figs.
Francis, A.J.; Dodge, C.J.
Effect of Environment on Fatigue Usage for Piping and Nozzles at Oconee Units 1, 2, and 3
This report describes an evaluation of stainless steel components in a pressurized water reactor and the effects of the water environment on the ASME Code Class 1 fatigue evaluation. The report provides an approach that can be used to evaluate the combination of quasi-steady, thermal transient, and dynamic loading effects to develop an environmental correction factor (Fen) that can be applied to individual load set pairs. The approach is applied to both nozzle and piping components and shows that environ...
Materials Design of Advanced Performance Metal Catalysts
The contribution of materials design to the fabrication of advanced metal catalysts is highlighted, with particular emphasis on the construction of relatively complex contact structures surrounding metal nanoparticles. Novel advanced metal catalysts can be synthesized via encapsulation of metal nanoparticles into oxide shells, immobilization of metal oxide core-shell structures on solid supports, post-modification of supported metal nanoparticles by surface coating, and premodification of supports before loading metal nanoparticles. Examples on how these materials structures lead to enhanced catalytic performance are illustrated, and a few future prospects are presented.
Ma, Zhen [ORNL; Dai, Sheng [ORNL
User`s manual for FAROW: Fatigue and reliability of wind turbine components: Version 1.1
FAROW is a Computer program that assists in the probabilistic analysis of the Fatigue and Reliability of wind turbines. The fatigue lifetime of wind turbine components is calculated using functional forms for important input quantities. Parameters of these functions are defined in an input file as either constants or random variables. The user can select from a library of random variable distribution functions. FAROW uses structural reliability techniques to calculate the mean time to failure, probability of failure before a target lifetime, relative importance of each of the random inputs, and the sensitivity of the reliability to all input parameters. Monte Carlo simulation is also available. This user`s manual is intended to provide sufficient information to knowledgeably run the program and meaningfully interpret the results. The first chapter provides an overview of the approach and the results. Chapter 2 describes the formulation and assumptions used in the fatigue life calculations. Each of the input parameters is described in detail in Chapter 3 along with hints and warnings on usage. An explanation of the outputs is provided in Chapter 4. Two example problems are described and solved in Chapter 5, one for the case where extensive data are available and the other with limited data where the uncertainty is higher. A typical input file and the output files for the example problems are included in the appendices.
Veers, P.S. [Sandia National Labs., Albuquerque, NM (United States); Winterstein, S.R.; Lange, C.H. [Stanford Univ., Stanford, CA (United States). Dept. of Civil Engineering; Wilson, T.A. [New Mexico Univ., Albuquerque, NM (United States). Engineering Research Inst.
Inert anode containing base metal and noble metal useful for the electrolytic production of aluminum
An inert anode for production of metals such as aluminum is disclosed. The inert anode comprises a base metal selected from Cu and Ag, and at least one noble metal selected from Ag, Pd, Pt, Au, Rh, Ru, Ir and Os. The inert anode may optionally be formed of sintered particles having interior portions containing more base metal than noble metal and exterior portions containing more noble metal than base metal. In a preferred embodiment, the base metal comprises Cu, and the noble metal comprises Ag, Pd or a combination thereof.
Ray, Siba P. (Murrysville, PA); Liu, Xinghua (Monroeville, PA)
Semiconductor assisted metal deposition for nanolithography applications
An article of manufacture and method of forming nanoparticle sized material components. A semiconductor oxide substrate includes nanoparticles of semiconductor oxide. A modifier is deposited onto the nanoparticles, and a source of metal ions are deposited in association with the semiconductor and the modifier, the modifier enabling electronic hole scavenging and chelation of the metal ions. The metal ions and modifier are illuminated to cause reduction of the metal ions to metal onto the semiconductor nanoparticles.
Rajh, Tijana (Naperville, IL); Meshkov, Natalia (Downers Grove, IL); Nedelijkovic, Jovan M. (Belgrade, YU); Skubal, Laura R. (West Brooklyn, IL); Tiede, David M. (Elmhurst, IL); Thurnauer, Marion (Downers Grove, IL)
Reversible photodeposition and dissolution of metal ions
A cyclic photocatalytic process for treating waste water containing metal and organic contaminants. In one embodiment of the method, metal ions are photoreduced onto the photocatalyst and the metal concentrated by resolubilization in a smaller volume. In another embodiment of the method, contaminant organics are first oxidized, then metal ions removed by photoreductive deposition. The present invention allows the photocatalyst to be recycled until nearly complete removal of metal ions and organic contaminants is achieved.
Foster, Nancy S. (Boulder, CO); Koval, Carl A. (Golden, CO); Noble, Richard D. (Boulder, CO)
Coated Metal Articles and Method of Making
The method of protectively coating metallic uranium which comprises dipping the metallic uranium in a molten alloy comprising about 20-75% of copper and about 80-25% of tin, dipping the coated uranium promptly into molten tin, withdrawing it from the molten tin and removing excess molten metal, thereupon dipping it into a molten metal bath comprising aluminum until it is coated with this metal, then promptly withdrawing it from the bath.
Boller, Ernest R.; Eubank, Lowell D.
Process for fabrication of metal oxide films
This invention is comprised of a method of fabricating metal oxide films from a plurality of reactants by inducing a reaction by plasma deposition among the reactants. The plasma reaction is effective for consolidating the reactants and producing thin films of metal oxides, e.g. electro-optically active transition metal oxides, at a high deposition rate. The presence of hydrogen during the plasma reaction enhances the deposition rate of the metal oxide. Various types of metal oxide films can be produced.
Tracy, C.E.; Benson, D.; Svensson, S.
Advances in metallic nuclear fuel
Metallic nuclear fuels have generated renewed interest for advanced liquid metal reactors (LMRs) due to their physical properties, ease of fabrication, irradiation behavior, and simple reprocessing. Irradiation performance for both steady-state and transient operations is excellent. Ongoing irradiation tests in Argonne-West's Idaho-based Experimental Breeder Reactor II (EBR-II) have surpassed 100,000 MWd/T burnup and are on their way to a lifetime burnup of 150,000 MWd/T or greater. Metallic fuel also has a unique neutronic characteristic that enables benign reactor responses to loss-of-flow without scram and loss-of-heat-sink without scram accident conditions. This inherent safety potential of metallic fuel was demonstrated in EBR-II just one year ago. Safety tests performed in the reactor have also demonstrated that there is ample margin to fuel element cladding failure under transient overpower conditions. These metallic fuel attributes are key ingredients of the integral fast reactor (IFR) concept being developed at Argonne National Laboratory.
Seidel, B.R.; Walters, L.C.; Chang, Y.I.
Zone refining of plutonium metal
The zone refining process was applied to Pu metal containing known amounts of impurities. Rod specimens of plutonium metal were melted into and contained in tantalum boats, each of which was passed horizontally through a three-turn, high-frequency coil in such a manner as to cause a narrow molten zone to pass through the Pu metal rod 10 times. The impurity elements Co, Cr, Fe, Ni, Np, U were found to move in the same direction as the molten zone as predicted by binary phase diagrams. The elements Al, Am, and Ga moved in the opposite direction of the molten zone as predicted by binary phase diagrams. As the impurity alloy was zone refined, {delta}-phase plutonium metal crystals were produced. The first few zone refining passes were more effective than each later pass because an oxide layer formed on the rod surface. There was no clear evidence of better impurity movement at the slower zone refining speed. Also, constant or variable coil power appeared to have no effect on impurity movement during a single run (10 passes). This experiment was the first step to developing a zone refining process for plutonium metal.
Blau, M.S.
Corrosion of Metals and Alloys in High Radiation Fields
This paper rationalizes the impact of high radiation fields on corrosion, hydrogen embrittlement and corrosion fatigue and relates that impact to radiation induced changes in chemical reactivity, hydrogen fugacity, and surface chemistry.
Sindelar, R.L.
Acoustic Emission and Guided Wave Monitoring of Fatigue Crack Growth on a Full Pipe Specimen
Continuous on-line monitoring of active and passive systems, structures and components in nuclear power plants will be critical to extending the lifetimes of nuclear power plants in the US beyond 60 years. Acoustic emission and guided ultrasonic waves are two tools for continuously monitoring passive systems, structures and components within nuclear power plants and are the focus of this study. These tools are used to monitor fatigue damage induced in a SA 312 TP304 stainless steel pipe specimen. The results of acoustic emission monitoring indicate that crack propagation signals were not directly detected. However, acoustic emission monitoring exposed crack formation prior to visual confirmation through the detection of signals caused by crack closure friction. The results of guided ultrasonic wave monitoring indicate that this technology is sensitive to the presence and size of cracks. The sensitivity and complexity of GUW signals is observed to vary with respect to signal frequency and path traveled by the guided ultrasonic wave relative to the crack orientation.
Meyer, Ryan M.; Cumblidge, Stephen E.; Ramuhalli, Pradeep; Watson, Bruce E.; Doctor, Steven R.; Bond, Leonard J.
Fatigue expectations in a molybdenum/silicon multilayer under pulsed soft X-ray radiation
The temperature rise in a Mo/a-Si multilayer x-ray reflective film due to radiation absorption is modeled for the first condenser mirror in a projection lithography system such as the one designed by the Advanced Microtechnology Program at LLNL. The radiation load is pulsed at 1000 Hz with a time average intensity of 500mW/cm{sup 2}. This intensity is the expected maximum on the first condenser mirror. The temperature rise is calculated using the integral transform technique. The film is assumed to have the thermal properties of its poorly conducting substrate, yielding a more conservative (higher) temperature estimate. The surface temperature rise is found to range between 35.6{degrees}C and 76.3{degrees}C. The stress due to this rise is greatest in the molybdenum film and ranges between 73MPa and 166MPa compressive. This fluctuating stress level, however, is believed to be insufficient, by a factor of five or so, to cause fatigue failure of the film.
Weber, F.J.; Kassner, M.E. [Oregon State Univ., Corvallis, OR (United States); Stearns, D.G. [Lawrence Livermore National Lab., CA (United States)
A Case for Including Atmospheric Thermodynamic Variables in Wind Turbine Fatigue Loading Parameter Identification
This paper makes the case for establishing efficient predictor variables for atmospheric thermodynamics that can be used to statistically correlate the fatigue accumulation seen on wind turbines. Recently, two approaches to this issue have been reported. One uses multiple linear-regression analysis to establish the relative causality between a number of predictors related to the turbulent inflow and turbine loads. The other approach, using many of the same predictors, applies the technique of principal component analysis. An examination of the ensemble of predictor variables revealed that they were all kinematic in nature; i.e., they were only related to the description of the velocity field. Boundary-layer turbulence dynamics depends upon a description of the thermal field and its interaction with the velocity distribution. We used a series of measurements taken within a multi-row wind farm to demonstrate the need to include atmospheric thermodynamic variables as well as velocity-related ones in the search for efficient turbulence loading predictors in various turbine-operating environments. Our results show that a combination of vertical stability and hub-height mean shearing stress variables meet this need over a period of 10 minutes.
Kelley, N. D.
A computer-controlled automated test system for fatigue and fracture testing
A computer-controlled system consisting of a servohydraulic test machine, an in-house designed test controller, and a desktop computer has been developed for performing automated fracture toughness and fatigue crack growth testing both in the laboratory and in hot cells for remote testing of irradiated specimens. Both unloading compliance and dc-potential drop can be used to monitor crack growth. The test controller includes a dc-current supply programmer, a function generator for driving the servohydraulic test machine to required test outputs, five measurement channels (each consisting of low-pass filter, track/hold amplifier, and 16-bit analog-to-digital converter), and digital logic for various control and data multiplexing functions. The test controller connects to the computer via a 16-bit wide photo-isolated bidirectional bus. The computer, a Hewlett-Packard series 200/300, inputs specimen and test parameters from the operator, configures the test controller, stores test data from the test controller in memory, does preliminary analysis during the test, and records sensor calibrations, specimen and test parameters, and test data on flexible diskette for later recall and analysis with measured initial and final crack length information. During the test, the operator can change test parameters as necessary. 24 refs., 6 figs.
Nanstad, R.K.; Alexander, D.J.; Swain, R.L.; Hutton, J.T.; Thomas, D.L.
Elevated-temperature fracture toughness and fatigue testing of steels for geothermal applications. Annual progress report
Conventional drill bit steels exhibit increased wear and decreased toughness when run at elevated temperatures in geothermal wells. Bits are therefore run at lower speeds and lighter loads, resulting in lower penetration rates for geothermal wells than for conventional rock drilling. Carpenter EX-00053, Timken CBS 600, Timken CBS 1000M and Vasco X-2M, steels with improved hot hardness (improved wear resistance), were tested in conjunction with the steels used for cones (AISI 4820 and 9315) and lugs (AISI 8620 and 9315) in conventional roller cone rock bits. Shortrod fracture toughness measurements were made on each of these steels between room temperature and 400/sup 0/C. Fatigue crack resistance was determined at 300/sup 0/C for high-temperature steels and at room temperature for conventional steels. Scanning electron microscopy analyses of the fractured short-rod specimens were correlated with observed crack behavior from the test records. Test results are discussed, recommendations made for further testing and preliminary steel selections made for improved geothermal bits.
Cutler, R.A.; Goodman, E.C.; Guest, R.V.; Hendrickson, R.R.; Leslie, W.C.
Variations in gear fatigue life for different wind turbine braking strategies
A large number of gearbox failures have occurred in the wind industry in a relatively short period, many because service loads were underestimated. High-torque transients that occur during starting and stopping are difficult to predict and may be overlooked in specifying gearbox design. Although these events comprise a small portion of total load cycles, they can be the most damaging. The severity of these loads varies dramatically with the specific configuration of the wind turbine. The large number of failures in Danish-designed Micon 65 wind turbines prompted this investigation. The high-speed and low-speed shaft torques were measured on a two-stage helical gearbox of a single Micon 65 turbine. Transient events and normal running loads were combined statistically to obtain a typical annual load spectrum. The pitting and bending fatigue lives of the gear teeth were calculated by using Miner's rule for four different high-speed shaft brake configurations. Each breaking scenario was run for both a high- and a low-turbulence normal operating load spectrum. The analysis showed increases in gear life by up to a factor of 25 when the standard high-speed shaft brake is replaced with a dynamic brake or modified with a damper. 9 refs., 9 figs., 3 tabs.
McNiff, B.P. (Second Wind, Inc., Somerville, MA (USA)); Musial, W.D. (Solar Energy Research Inst., Golden, CO (USA)); Errichello, R. (GEARTECH, Albany, CA (USA))
Fatigue Testing of Metallurgically-Bonded EBR-II Superheater Tubes
Fatigue crack growth tests were performed on 2�Cr-1Mo steel specimens machined from ex-service Experimental Breeder Reactor � II (EBR-II) superheater duplex tubes. The tubes had been metallurgically bonded with a 100 �m thick Ni interlayer; the specimens incorporated this bond layer. Tests were performed at room temperature in air and at 400�C in air and humid Ar; cracks were grown at varied levels of constant ?K. Crack growth tests at a range of ?K were also performed on specimens machined from the shell of the superheater. In all conditions the presence of the Ni interlayer was found to result in a net retardation of growth as the crack passed through the interlayer. The mechanism of retardation was identified as a disruption of crack planarity and uniformity after passing through the porous interlayer. Full crack arrest was only observed in a single test performed at near-threshold ?K level (12 MPa?m) at 400�C. In this case the crack tip was blunted by oxidation of the base steel at the steel-interlayer interface.
Terry C. Totemeier
Fatigue reliability of wind turbine fleets: The effect of uncertainty of projected costs
The cost of repairing or replacing failed components depends on the number and timing of failures. Although the total probability of individual component failure is sometimes interpreted as the percentage of components likely to fail, this perception is often far from correct. Different amounts of common versus independent uncertainty can cause different numbers of components to be at risk of failure. The FAROW tool for fatigue and reliability analysis of wind turbines makes it possible for the first time to conduct a detailed economic analysis of the effects of uncertainty on fleet costs. By dividing the uncertainty into common and independent parts, the percentage of components expected to fail in each year of operation is estimated. Costs are assigned to the failures and the yearly costs and present values are computed. If replacement cost is simply a constant multiple of the number of failures, the average, or expected cost is the same as would be calculated by multiplying by the probability of individual component failure. However, more complicated cost models require a break down of how many components are likely to fail. This break down enables the calculation of costs associated with various probability of occurrence levels, illustrating the variability in projected costs. Estimating how the numbers of components expected to fail evolves over time is also useful in calculating the present value of projected costs and in understanding the nature of the financial risk.
Thin films of mixed metal compounds
Disclosed is a thin film heterojunction solar cell, said heterojunction comprising a p-type I-III-IV[sub 2] chalcopyrite substrate and an overlying layer of an n-type ternary mixed metal compound wherein said ternary mixed metal compound is applied to said substrate by introducing the vapor of a first metal compound to a vessel containing said substrate from a first vapor source while simultaneously introducing a vapor of a second metal compound from a second vapor source of said vessel, said first and second metals comprising the metal components of said mixed metal compound; independently controlling the vaporization rate of said first and second vapor sources; reducing the mean free path between vapor particles in said vessel, said gas being present in an amount sufficient to induce homogeneity of said vapor mixture; and depositing said mixed metal compound on said substrate in the form of a uniform composition polycrystalline mixed metal compound. 5 figs.
Mickelsen, R.A.; Chen, W.S.
In the utilization of nuclear heat energy, liquid metal could be used in a vapor cycle to propel a column of liquid metal in a jet pump or injector where electrical energy could be extracted by means of a MHD arrangement. The recirculating system is being studied as a means of increasing the efficiency. Results are described briefly for a preliminary run made using steam and water; the efficiency of conversion of steam kinetic energy to liquid kinetic energy was approximates 20%. The possible causes of the low efficiency and some of the methods for decreasing hydraulic losses are outlined. (D.L.C.)
Sowa, E.S.
Cerenkov radiation in metallic metamaterials
The electromagnetic response of a metallic metamaterial to fast-moving electrons is studied by numerical simulations. The considered metamaterial is a one-dimensional array of slits perforated on a metallic film and is found to generate Cerenkov wakes when the electron beam travels near its surface. There is no energy threshold for the generation of such wakes, which would be promising to lower the operation energy of the electron beam in compact Cerenkov free-electron-lasers. Moreover, by analyzing the spectral dependence of the Cerenkov light, it is possible to map the dispersion relation of the guided modes supported by the metamaterial.
So, Jin-Kyu; Won, Jong-Hyo; Sattorov, M. A.; Bak, Seung-Ho; Jang, Kyu-Ha; Park, Gun-Sik [Department of Physics and Astronomy, Center for THz-Bio Application Systems, Seoul National University, Seoul 151-747 (Korea, Republic of); Kim, D. S. [Department of Physics and Astronomy, Center for Subwavelength Optics, Seoul National University, Seoul 151-747 (Korea, Republic of); Garcia-Vidal, F. J. [Departamento de Fisica Teorica de la Materia Condensada, Universidad Autonoma de Madrid, E-28049 Madrid (Spain)
Cleaning fluids for removing deposits from metal surfaces are described. The cleaning agents of the invention consist of aqueous nitric acid and an amhydrous nitrate salt of a metal which is lower in the electromotive series than the element of the deposit to be removed. In general, the salt content of thc cleaning agents ranged from 10 to 90%, preferably from 10 to 40% by weight; and the balance of the composition comprises nitric acid of any strength from extremely dilute up to concentrated strength.
Winkler, H.W.; Morfitt, J.W.; Little, T.H.
Metal-On-Metal Bonding and Rebonding Revisited
Density-functional calculations for a wide variety of metals show that, contrary to the rebonding view of adsorbate bonding, addimers do not have notably longer surface bonds than adatoms, do not reside farther above the surface, and do not meet the rebonding arguments for augmented mobility. Rebonding concepts are found to have some utility in explaining addimer stability.
Bogicevic, A.
Metal oxide and metal fluoride nanostructures and methods of making same
The present invention includes pure single-crystalline metal oxide and metal fluoride nanostructures, and methods of making same. These nanostructures include nanorods and nanoarrays.
Wong, Stanislaus S. (Stony Brook, NY); Mao, Yuanbing (Los Angeles, CA)
Thermal barrier and overlay coating systems comprising composite metal/metal oxide bond coating layers
The present invention generally describes multilayer coating systems comprising a composite metal/metal oxide bond coat layer. The coating systems may be used in gas turbines.
Goedjen, John G. (Oviedo, FL); Sabol, Stephen M. (Orlando, FL); Sloan, Kelly M. (Longwood, FL); Vance, Steven J. (Orlando, FL)
Stabilization of Electrocatalytic Metal Nanoparticles at Metal-Metal Oxide-Graphene Triple Junction Points
Carbon-supported metal catalysts are widely used in heterogeneous catalysis and electrocatalysis. In this paper, we report a novel method to deposit metal catalysts and metal oxide nanoparticles on two-dimensional graphene sheets to improve the catalytic performance and stability of the catalyst materials. The new synthesis method allows indium tin oxide (ITO) nanocrystals to be directly grown on functionalized graphene sheets forming the ITO-graphene hybrids. Pt nanoparticles are then deposited to form a special triple-junction structure (Pt-ITO-graphene). Both experimental study and periodic density functional theory calculations show that the supported Pt nanoparticles are stable at Pt-ITO-graphene triple junction points. The new catalyst materials were tested for oxygen reduction for potential applications in polymer electrolyte membrane fuel cells, and they exhibited greatly enhanced stability and activity. The reasons for the high stability and activity of Pt-ITO-graphene are analyzed.
Kou, Rong; Shao, Yuyan; Mei, Donghai; Nie, Zimin; Wang, Donghai; Wang, Chong M.; Viswanathan, Vilayanur V.; Park, Seh K.; Aksay, Ilhan A.; Lin, Yuehe; Wang, Yong; Liu, Jun
Hydrothermal alkali metal catalyst recovery process
In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles primarily in the form of water soluble alkali metal formates by treating the particles with a calcium or magnesium-containing compound in the presence of water at a temperature between about 250.degree. F. and about 700.degree. F. and in the presence of added carbon monoxide. During the treating process the water insoluble alkali metal compounds comprising the insoluble alkali metal residues are converted into water soluble alkali metal formates. The resultant aqueous solution containing water soluble alkali metal formates is then separated from the treated particles and any insoluble materials formed during the treatment process, and recycled to the gasification process where the alkali metal formates serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst. This process permits increased recovery of alkali metal constituents, thereby decreasing the overall cost of the gasification process by reducing the amount of makeup alkali metal compounds necessary.
Eakman, James M. (Houston, TX); Clavenna, LeRoy R. (Baytown, TX)
Transition metal sulfide loaded catalyst
A zeolite-based catalyst is described for activation and conversion of methane. A zeolite support includes a transition metal (Mo, Cr or W) sulfide disposed within the micropores of the zeolite. The catalyst allows activation and conversion of methane to C[sub 2]+ hydrocarbons in a reducing atmosphere, thereby avoiding formation of oxides of carbon.
Maroni, V.A.; Iton, L.E.; Pasterczyk, J.W.; Winterer, M.; Krause, T.R.
Machinable dissolved metal oxide superconductors
Powders of a metal oxide superconductor are mixed with sufficient amount (10--80 mol%) of In, Sn, and/or Al, to become nonbrittle, machinable. Preferred superconductors are YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} and Bi-Sr-Ca-Cu-O compounds.
Chen, Chung-Hsuan
Powders of a metal oxide superconductor are mixed with sufficient amount (10--80 mol%) of In, Sn, and/or Al, to become nonbrittle, machinable. Preferred superconductors are YBa[sub 2]Cu[sub 3]O[sub 7[minus]x] and Bi-Sr-Ca-Cu-O compounds.
Chen, Chung-Hsuan.