Wear characteristics of Ti-Nb-Ta-Zr and Ti-6Al-4V alloys for biomedical applications

Abstract

The influences of heat treatment, variation in Nb content, surface modification and counterface materials on the wear characteristics of new β type Ti-Nb-Ta-Zr alloys and conventional metallic implant alloy Ti-6Al-4V were investigated, using a reciprocal pin-on-disc wear device in a 0.9% NaCl solution. For the wear test of sliding on stainless steel disc, experimental results show that the wear resistance of Ti-29Nb-13Ta-4.6Zr and Ti-6Al-4V is insensitive to their mechanical properties, such as hardness and ultimate tensile strength. Increase in Nb content results in an improvement of the wear resistance of the β type alloy to some degree. The wear resistance of Ti-29Nb-13Ta-4.6Zr improved significantly after oxidation treatment, due to the presence of Nb2O5oxide particles on the diffusion hardened surface of the alloy. For wear test of sliding on ultra-high molecular weight polyethylene (UHMWPE) and bone of pig, the wear losses of both Ti-Nb-Ta-Zr and Ti-6Al-4V are much less compared with that sliding on stainless steel and there is almost no wear on the surface of oxided Ti-29Nb-13Ta-4.6Zr. © 2004 Elsevier B.V. All rights reserved.