Comparative, real-time in situ monitoring of galvanic corrosion in Mg-Mg2Ca and Mg-MgZn2 couples in Hank's solution

The purpose of this study is to comparatively investigate on intermetallic compounds Mg2Ca and MgZn2 in galvanic corrosion of magnesium alloy by using real-time in situ monitoring techniques. The results indicated Mg2Ca functioned as an anode with higher anodic current density, higher Mg2+ concentration and higher pH values than the Mg cathode, while MgZn2 worked as a cathode with a cathodic current density, lower Mg2+ concentration and higher pH value than the anodic Mg. The results also suggested a corrosion forming mechanism involving solubility product constant (K-sp) in which Zn-based corrosion products were easier to form than their Mg counterparts.