Stress Assisted Dissolution of Biomedical Grade CoCrMo: Influence of Contact Loads and Residual Stresses

Mechanical load assisted dissolution is identified as one of the key mechanisms governing material removal in fretting and crevice corrosion of biomedical implants. In the current study, material removal on a stressed surface of cobalt-chromium-molybdenum (CoCrMo) subjected to single asperity contact was investigated in order to identify the influence of contact load and residual stress on dissolution rates. A range of known stress levels were applied to the specimen while the surface was mechanically stimulated in ambient conditions as well as different aqueous environments ranging from non-reactive to oxidizing. Dissolution rate was found to display a complex dependence on residual stress and environment.