Effect of the graphene oxide additive on the corrosion resistance of the plasma electrolytic oxidation coating of the AZ31 magnesium alloy

Graphene oxide (GO) was added into the electrolyte during the preparation of the plasma electrolytic oxidation (PEO) coating on AZ31 magnesium alloy. The effects of the GO additive on the microstructure, phase composition, and corrosion resistance of the PEO coating were studied. The results demonstrated that GO successfully incorporated into the PEO coating and it was partially reduced to rGO during the PEO process. As a result, the number of micropores on the PEO coating was significantly decreased. Moreover, the electrochemical test revealed that the corrosion resistance of the PEO coating was markedly improved upon the incorporation of 2 g/L GO.