Co-Cr alloy, SUS 316L stainless steel, pure Ti and Ti-6Al-4V ELI have been used as implant materials. Ti-6Al-4V ELI has been most widely used as an implant material to date because of its excellent combination of biocompatibility, corrosion resistance and mechanical properties. Since toxicity of V etc., and high moduli of elasticity have been pointed out, β-type biomedical titanium alloys are recently getting much attentions. New β-type biomedical titanium alloys composed of non-toxic elements such as Nb, Ta, Mo, Zr and Sn with lower moduli of elasticity and greater strength were, therefore, designed using alloy design method based on the d-electron theory in this study.
Tensile test, measurement of modulus of elasticity and evaluation of biocompatibility were conducted in order to investigate the mechanical properties and biocompatibility of the designed alloy. Tensile strength and elongation of Ti-29Nb-13Ta-4.6Zr are, in particular, equivalent to those of conventional biomedical titanium alloy such as Ti-6Al-4V ELI, and modulus of elasticity of Ti-29Nb-13Ta-4.6Zr is lower than that of Ti-6Al-4V ELI. The moduli of elasticity of the designed alloys are equivalent or lower comparing with those of conventional biomedical titanium alloys such as Ti-6Al-4V ELI and Ti-13Nb-13Zr. The biocomparibility of Ti-29Nb-13Ta-4.6Zr is equivalent to pure-Ti, and biocompatibility of Ti-29Nb-13Ta-4.6Zr is much greater than that of Ti-6Al-4V.
The new β-type titanium alloy, Ti-Nb-Ta-Zr, designed in this study is expected to have greater performance for implant materials.
