Influence of mixed rare earth elements(Y and Ce) on the microstructure and corrosion behaviour of Mg-4Al-3Ca alloy

Abstract

Microstructure of Mg-Al-Ca based alloys was studied by using x-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe microanalyzer (EPMA). Corrosion morphologies and corrosion behaviour of the alloys were analysed using static weight loss test, electrochemical characterization and SEM imaging. The results reveal that when adding mixed rare earth (RE) elements (Y and Ce) to Mg-4Al-3Ca alloy, the thick strip shaped (Mg,Al)2Ca phase was refined and the continuity was changed. Granular Al-RE phase was distributed in the matrix. The Mg-4Al-3Ca-0.5RE alloy has the best corrosion resistance, which is attributed to the combination of a good corrosion barrier, a suitable amount of precipitate phases and a small amount of RE elements addition on the purification of the alloy.