Effects of solidifi cation cooling rate on the corrosion resistance of Mg – Zn–Ca alloy

This study was carried out to investigate the effect of solidification cooling rate on the corrosion resistance of an Mg–Zn–Ca alloy developed for biomedical applications. A wedge shaped copper mould was used to obtain different solidification cooling rates. Electrochemical and immersion tests were employed to measure the corrosion resistance of Mg–Zn–Ca alloy. It was found that increasing cooling rate resulted in a significant improvement in the corrosion resistance of the Mg–Zn–Ca alloy. The findings were explained in terms of solidification behaviour in association with the change in solubility of the alloying elements, microstructural homogeneity and refinement and chemical homogeneity as well as the increased cooling rates.