Influence of microstructure of HC CoCrMo biomedical alloys on the corrosion and wear behaviour in simulated body fluids

The corrosion and tribological behaviour of an as-cast High Carbon CoCrMo alloy subjected to different thermal treatments in simulated body fluids has been analyzed by electrochemical techniques. After the microstructural characterization of the alloy, the samples were studied electrochemically and tribo-electrochemically. Thermal treatments influence the corrosion behaviour, passive dissolution and tribological response. An increase of grain boundaries accelerates the anodic reaction in all solutions. A higher carbide volume fraction generates a lower wear-rate. Microscopic observation by means of Optical and SEM microscopy showed that presence of proteins modified the debris behaviour. In non-protein containing solutions particles are dispersed away from the track while in protein solutions particles tend to agglomerate and sediment around the wear track.