Nb-Ti-Zr alloys for orthopedic implants

Niobium (Nb), Titanium (Ti), and Zirconium (Zr) have attracted much attention as implant materials due to it's excellent mechanical properties and biocompatibility. However, little attention has been paid to high Nb-containing biomedical alloys. Here, the 50 wt.%Nb-XTi-Zr ternary alloy(x = 20wt.%, 30 wt.%, 40 wt.%) with relative density over 90% was prepared by powder metallurgy method. The massive alpha(Zr) distributed along the grain boundaries and lamellar beta(Zr) appeared in the grains of beta(Nb) in the 50 wt.%Nb-20wt.%Ti-Zr alloy. The acicular alpha phase is mainly distributed in the beta-grain of 50 wt.%Nb-30wt.%Ti-Zr alloy. And alpha(Ti)-colonies in the beta-grains and continuous alpha(Ti)(GB) at beta-grain boundary can be observed in the 50 wt.%Nb-40wt.%Ti-Zr alloy. Comparing with Nb-20wt.%Ti-Zr alloy and 50 wt.%Nb-40wt.%Ti-Zr alloy, the 50 wt.%Nb-30wt.%Ti-Zr alloy showed lower Vickers hardness and elastic modulus. Furthermore, the as-sintered 50 wt.%Nb-XTi-Zr alloy promoted the cell proliferation and cell adhesion of MG-63 cells on the surface of alloys. In conclusion, the 50 wt.%Nb-XTi-Zr alloy combines excellent mechanical and biological properties, and the 50 wt.%Nb-30wt.%Ti-Zr alloy with lower elastic modulus (close to the bone) is a more promising candidate for bone implant material.

Automated summary

Niobium (Nb), Titanium (Ti), and Zirconium (Zr) are materials attracting attention for implants due to their excellent properties. A ternary alloy of 50 wt.%Nb-30wt.%Ti-Zr showed lower Vickers hardness, elastic modulus, and promoted cell proliferation and adhesion of MG-63 cells. This alloy may be a promising candidate for bone implant material.