Microstructural effects on the wear resistance of wrought and as-cast Co-Cr-Mo-C implant alloys.

The tribological behavior of two cobalt-base alloys-an as-cast high-carbon and a wrought low-carbon Co alloy-that are used as hip implant materials is examined in this work. This work discusses the experimental results of cobalt-cobalt wear pairs, in wrought and as-cast conditions, where the amount of hexagonal phase is systematically modified through an isothermal aging treatment. Fully FCC and HCP Co alloys are tested versus alloys with various volume fractions of HCP phase (0.05 to 1.0 volume fractions). Preliminary results indicate that Co-Cr-Mo/Co-Cr-Mo alloy pairs both possessing an HCP matrix microstructure tend to exhibit outstanding wear properties.