A Compilation of Corrosion Potentials for Magnesium Alloys

A compilation of the reported corrosion potentials for Mg alloys and selected intermetallic compounds is presented. This study presents a galvanic series for Mg alloys based on a collection of data reported elsewhere, along with some experimental results. The paper classifies the relative potential bands that are realized as a result of alloying Mg. It is observed that the corrosion potential range of crystalline alloys, regardless of composition, remains rather narrow and in all cases <<1 V vs. the standard hydrogen electrode (SHE). Alloys containing Ca and commercial alloys containing large rare earth (RE) alloying content possess the most negative corrosion potentials while the aluminum zinc (AZ) series of alloys, along with magnesium-based metallic glasses, possess the most noble corrosion potentials. The work described is intended as a holistic summary and a guide in the context of galvanic relationships, in addition to providing a better insight in to the electrochemical character of commercial and experimental Mg alloys when viewed overall.