The corrosion of CoCrMo alloys for biomedical applications

CoCrMo alloys have been used for biomedical implants for a number of years. They are now frequently used for the metal-on-metal hip resurfacing joints due to their high corrosion and wear performance. The present project was carried out to investigate the feasibility of taking electrochemical measurements from hip resurfacing joints whilst articulating in a hip simulator. In this study, the effect of ‘as-cast’ and ‘double heat-treated’ CoCrMo alloys were compared for microstructure and corrosion behaviour differences while operating in a hip simulator. Corrosion behaviour was investigated using a ProSim friction simulator with an integrated electrochemical cell in this study of tribocorrosion. OCP and potentiostat measurements were taken using 3.5% NaCl and 28% bovine in the hip simulator. Potentiodynamic polarisation curves were taken in neutral and acidified bovine serum solutions. The problems and changing variables that occur as a result of corrosion testing in a hip simulator were identified and discussed, most notably the change in temperature and its affect on the corrosion potential. 3.5% NaCl was shown to be a more corrosive environment than 28% bovine serum in an articulating hip simulator under load. Preliminary potentiostat measurements in a hip simulator were taken, which to date, is the first of their kind.

Name dc:type.qualificationname

m_rs

Level dc:type.qualificationlevel

m_rs

Grantor dc:publisher.institution

University of Birmingham

Year dc:date.issued

2010

Author dc:creator

• Bellefontaine, George

• TN Mining engineering. Metallurgy