Effect of Manganese on Discharge and Corrosion Performance of Magnesium Alloy AP65 as Anode for Seawater-Activated Battery

Magnesium alloys AP65 with and without 0.3% (mass fraction) manganese additions were prepared by melting and casting. Their discharge and corrosion behavior in 3.5% sodium chloride (NaCl) solution was investigated with electrochemical measurement, immersion testing, and corrosion morphology observation. The results show that manganese promotes the grain refinement and reduces the self corrosion rate of AP65 alloy. Magnesium alloy AP65 added with manganese provides a more negative discharge potential than that without the addition of manganese, attributed to the homogeneously distributed Al11Mn4 particles, which facilitate the self-peeling of corrosion products during the discharge process. This means that the discharge and corrosion performance of AP65 alloy can be improved by adding manganese.