Abstract:

In order to explore an effective method to fabricate biomedical Ti alloy with high strength and low modulus,amorphous /nanocrystallized ( Ti_{69. 7}Nb_{23. 7}Zr_{4. 9}Ta_{1. 7} ) _{100 －x}Fe_x alloy powders with different Fe contents were synthesized via mechanical alloying,and,subsequently,ultrafine-grained Ti-based composites with high strength and low modulus were fabricated via the spark plasma sintering-amorphous crystallization. The results show that,during the performed mechanical alloying,Fe content significantly affects the glass-forming ability of the alloy system,concretely,fully amorphous structure forms only when x reaches 10; and that Fe content also has an obvious effect on the mechanical properties of the bulk composites,only the bulk composite at a x value of 6 possesses high strength and distinct plasticity,with the corresponding compressive yield stress,fracture stress and fracture strain respectively being 2425MPa,2650MPa and 0. 0691,and with an average elastic modulus of 52 GPa that is close to the minimum of the third-generation biomedical Ti alloys. Moreover,by comparing the friction and wear properties of the fabricated composites with those of two kinds of conventional biomedical Ti alloys ( Ti_{69. 7}Nb_{23. 7}Zr_{4. 9}Ta_{1. 7} ) ₉₄Fe₆,it is found that the fabricated composites are of the best wear resistance.

Key words: powder metallurgy, titanium alloy, composite, biomedical material, mechanical property, wear resistance