Wear mapping of CoCrMo alloy in simulated bio-tribocorrosion conditions of a hip prosthesis bearing in calf serum solution.

Wear maps were developed following a series of micro-abrasion-corrosion testing during idealised hip contact conditions for a CoCrMo alloy in a foetal calf serum solution. The main aim of the study was to characterise wear-corrosion or bio-tribocorrosion regimes of the alloy over a range of applied loads and applied potentials. The transitioning micro-abrasion-corrosion mechanisms, synergisms and wastage behaviours in the presence of additional abrasive particles were identified and mapped. Wear maps in earlier work show the wear-corrosion transitions of CoCrMo alloy in the absence of abrasive particles for similar conditions; the wear maps developed in this work were compared. Mapping the micro-abrasion-corrosion regimes indicated that proteins present in foetal calf serum solution, resulting in development of a graphitic tribo-layer, may play a critical role in enhancing or protecting against tribo-corrosive degradation.