Microstructure and mechanical properties of Ti-Zr-Cr biomedical alloys

The Ti-15Zr-xCr (0 ≤ x ≤ 10, wt.%) alloys were investigated to develop new biomedical materials. It was found that the phase constitutions and mechanical properties strongly depended on the Cr content. The Ti-15Zr alloy was comprised of α′ phase and a small fraction of β phase was detected with adding 1 wt.% Cr. With addition of 5 wt.% or more, the β phase was completely retained. In addition, the ω phase was detected in the Ti-15Zr-5Cr alloy and Ti-15Zr-7Cr alloy which exhibited the highest compressive Young's modulus and the lowest ductility. On the other hand, all the Ti-15Zr-xCr alloys without ω phase exhibited high microhardness, high yield strength and superior ductility. Furthermore, the elastic energy of Ti-15Zr-10Cr alloy (5.89 MJ/m3) with only β phase and that of Ti-15Zr-3Cr alloy (4.04 MJ/m3) with α′ phase and small fraction of β phase was higher than the elastic energy of c.p. Ti (1.25 MJ/m3). This study demonstrated that Ti-15Zr-3Cr alloy and Ti-15Zr-10Cr alloy with superior mechanical properties are potential materials for biomedical applications.