Study of wear-corrosion resistance of Co-based biomaterial

The longevity and the safety of artificial joint implants are determined by wear and corrosion properties. For many clinical cases, the released metallic ions and wear debris can cause adverse tissue reactions. Eventually, failure of such medical devices can be induced. Therefore, it is of great interest to increase the wear-corrosion resistance of implant materials. The release of metallic ions is related to the damage on the passive film which can spontaneously form on the surface of the cobalt-chromium-molybdenum (CoCrMo) alloy. In order to prevent the tribocorrosion reaction ( the interaction between tribology and corrosion), a titanium nitride (TiN) film was applied on the surface by magnetron sputtering technology. The tribocorrosion behaviours of the titanium nitride and cobalt-chromium-molybdenum combination were studied. It has been shown that titanium nitride can greatly increase tribocorrosion resistance. However, if the titanium nitride film is damaged by tribological contact or the impact of the contact, the corrosion rate would dramatically increase.