Bio-Corrosion of Magnesium Alloys for Orthopaedic Applications

Three Mg alloys, Mg-1.34% Ca-3% Zn (MCZ), Mg-1.34% Ca-3% Zn-0.2% Sr (MCZS), and Mg-2% Sr (MS), were examined to understand their bio-corrosion behavior. Electrochemical impedance spectroscopy and polarization scans were performed after 6 days of immersion in cell culture medium, and ion release and changes in media pH were tracked over a 28 day time period. Scanning electron microscopy (SEM) of alloy microstructure was performed to help interpret the results of the electrochemical testing. Results indicate that corrosion resistance of the alloys is as follows: MCZ > MCZS > MS.