Date of Award
The past few decades have seen an increase in the use of beta titanium alloys as structural biomaterials. Their combination of excellent mechanical properties, corrosion resistance and biocompatibility, along with a lower Young’s modulus than stainless steel, cobalt-chromium and commercially pure titanium make the beta titanium alloys ideal biomaterials. This work evaluates the use of three beta titanium alloys for biomedical applications. Three beta titanium alloys, Ti 15-3-3-3, Ti SP-700 and Ti Beta-C, underwent thermal processing to optimize mechanical properties. The alloys were subjected to tensile testing, hardness testing, fatigue testing, optical microscopy and SEM fracture analysis in order to determine the best processing conditions for biomedical alloys. In order to understand the effects of the thermal processing, the grain structures of the beta titanium alloys were examined. The fracture surfaces of the alloys were examined to understand the fracture and failure mechanisms involved. Thermal processing yielded good properties (998 MPa and 23% elongation) in the Ti 15-3-3-3 alloy aged at 550 ºC. The annealed condition of the Ti SP-700 produced good mechanical properties for biomedical applications (1031 MPa and 27% elongation). Titanium Beta-C aged at 455 ºC yielded good mechanical properties (964 MPa and 23% elongation). However, the Ti Beta-C alloy’s mechanical properties can be improved upon still by implementing a duplex aging process. All three alloys fractured in a ductile manner, which is desired for structural alloys. All three alloys, Ti 15-3-3-3, Ti SP-700 and Ti Beta-c, can be processed to have good mechanical properties for biomedical applications, a combination of high strength (1000 MPa) and ductility (15% elongation).
Wood, Ethan, "Thermal Processing and Mechanical Properties of Beta Phase Titanium Alloys for Biomedical Applications" (2015). Graduate Theses & Non-Theses. 26.