influence the microstructure of the product, where e.g. a fast cooling rate in combination with low degree of melting in SLM leads to the predominant formation of martensitic alpha-prime phase, giving a very hard product. Ti-6Al-4V / Ti-6Al-4V-ELI This alloy has good biocompatibility, and is neither cytotoxic nor genotoxic. Ti-6Al-4V suffers from poor shear strength and poor surface wear properties in certain loading conditions:Bio compatibility: Excellent, especially when direct contact with tissue or bone is required. Ti-6Al-4V's poor shear strength makes it undesirable for bone screws or plates. It also has poor surface wear properties and tends to seize when in sliding contact with itself and other metals. Surface treatments such as nitriding and oxidizing can improve the surface wear properties. Ti-6Al-7Nb This alloy was developed as a biomedical replacement for Ti-6Al-4V, because Ti-6Al-4V contains vanadium, an element that has demonstrated cytotoxic outcomes when isolated. Ti-6Al-7Nb contains 6% aluminium and 7% niobium.Ti6Al7Nb is a dedicated high strength titanium alloy with excellent biocompatibility for surgical implants. Used for replacement hip joints, it has been in clinical use since early 1986. References Notes Sources External links http://www.tifab.com/subpages/tech_spec_grades.htm Datasheet for Beta Titanium Titanium Alloy Bar Phase Stability and Stress-Induced Transformations in Beta Titanium Alloys Orthodontics