Predicting the steady state thickness of passive films with the point defect model in fretting corrosion experiments

International audienceThe Point Defect model (PDM), was developed in early 1980s to provide an atomic scale account of passivity. Understanding and predicting the passivity of metals is a fundamental challenge to maintaining our 'metals-based civilization'. Three generations of this model have been devised and a fourth is under development. The third generation is currently being applied to fretting corrosion, which is corrosion in the presence of friction under small displacements. The parameters of the point defect model can be extracted through the interpretation of the Faradaic impedance measured via electrochemical impedance spectroscopy (EIS). These parameters can then be used to explain and predict behavior of the film. The experimental apparatus was designed specifically for this type of investigation in a previous paper. This work employs the Point Defect Model to account for enhanced fretting corrosion of 316L stainless steel wearing against poly methyl methacrylate