title: Fretting corrosion of CoCr alloy: Effect of load and displacement on the degradation mechanisms.
abstract: Fretting corrosion of medical devices is of growing concern, yet, the interactions between tribological and electrochemical parameters are not fully understood. Fretting corrosion of CoCr alloy was simulated, and the components of damage were monitored as a function of displacement and contact pressure. Free corrosion potential (Ecorr), intermittent linear polarisation resistance and cathodic potentiostatic methods were used to characterise the system. Interferometry was used to estimate material loss post rubbing. The fretting regime influenced the total material lost and the dominant degradation mechanism. At high contact pressures and low displacements, pure corrosion was dominant with wear and its synergies becoming more important as the contact pressure and displacement decreased and increased, respectively. In some cases, an antagonistic effect from the corrosion-enhanced wear contributor was observed suggesting that film formation and removal may be present. The relationship between slip mechanism and the contributors to tribocorrosion degradation is presented.
authors.affiliation: Institute of Functional Surfaces (iFS), School of Mechanical Engineering, University of Leeds, Leeds, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Bryant
authors.affiliation: Institute of Functional Surfaces (iFS), School of Mechanical Engineering, University of Leeds, Leeds, UK.
authors.forename: Anne
authors.initials: A
authors.lastname: Neville
mesh_terms: D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D002858:Chromium Alloys; D003035:Cobalt; D003343:Corrosion; D055664:Electrochemical Techniques; D019544:Equipment Failure Analysis; D006801:Humans; D008422:Materials Testing; D008982:Molybdenum; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D002858:Chromium Alloys; D003035:Cobalt; D008982:Molybdenum
keywords: CoCrMo alloy; Fretting corrosion; contact mechanics; tribocorrosion