text: Various techniques are used in the investigative process of metallurgical failure analysis.
  * Macroscopic examination: camera, stereoscope
  * Microscopic examination: light microscopy, electron microscopy, x-ray microscopy, metallographic etching
  * Mechanical testing: hardness testing, tensile testing, Charpy impact testing
  * Chemical testing: microprobe analysis, energy dispersive spectroscopy 
  Non-destructive testing: Non-destructive testing is a test method that allows certain physical properties of metal to be examined without taking the samples completely out of service. NDT is generally used to detect failures in components before the component fails catastrophically. 
  Destructive testing: Destructive testing involves removing a metal component from service and sectioning the component for analysis. Destructive testing gives the failure analyst the ability to conduct the analysis in a laboratory setting and perform tests on the material that will ultimately destroy the component.