Influence of Ca on the corrosion properties of magnesium for biomaterials

Abstract

The corrosion properties of a Mg alloy with Ca in Hank's solution were investigated by the hydrogen evolution test. In the test results, the hydrogen evolution rate increased with increasing Ca content. This phenomenon was caused by the precipitation of Mg2Ca phase in large amounts on the Mg matrix. In the case of Mg-Ca alloy, the formation of a micro-galvanic cell between the Mg2Ca phase and Mg matrix accelerated the preferred dissolution of the matrix. These results demonstrated that the corrosion resistance and hydrogen evolution rate are controlled by the Mg2Ca phase distribution in the Mg-Ca alloy system. (C) 2008 Elsevier B.V. All rights reserved.