A beta type
titanium alloy, Ti-29Nb-13Ta-4.6Zr, was newly designed and developed for biomedical applications. The new
alloy contains non-toxic elements such as Nb, Ta, and Zr. In the present study, phases that appeared in the new
alloy through various aging treatments were characterized by hardness tests and microstructural observations in order to identify the phase transformation.
Fatigue properties of the new
alloy were investigated. Young's modulus and cyto-toxicity of the new
alloy were also evaluated. Precipitated phases distribute homogeneously over the whole specimen, and they are alpha phase, a small amount of omega phase, and beta phase when the new
alloys are subjected to aging treatment at 673K for 259.2ks after
solution treatment at 1063K for 3.6ks. The
fatigue strength of the new
alloy subjected to aging at 673K for 259.2ks after
solution treatment at 1063K for 3.6ks is much better than when subjected to other aging treatments. In this case, the
fatigue limit is around 700MPa. Young's modulus of the new
alloy is much smaller than that of Ti-6Al-4V ELI. The cyto-toxicity of the new
alloy is equivalent to that of pure Ti. Therefore, it is proposed that the new
alloy, Ti-29Nb-13Ta-4.6Zr, will be of considerable use in biomedical applications.