Corrosion protection utilizing Ag layer on Cu coated AZ31 Mg alloy

This study investigated the corrosion protection by electrodeposited copper layer on AZ31 Mg alloy with and without additional silver layer. The single copper layer electrodeposited on AZ31 from copper pyrophosphate bath exhibited nodular structure and crevices between the nodules which resulted in the rapid initiation of pitting corrosion. Employing an additional electrodeposited silver layer onto the copper deposited AZ31 alloy decreased the number of imperfections and changed structure of electrodeposited copper from nodular to fine particle type resulting in improved corrosion resistance. This study further revealed that triple-layer coating of Cu/Ag/Cu exhibited the most efficient corrosion protection of AZ31 Mg alloy.