Hydrophobic surface contained Ca and/or Ce myristate fabricated on AZ31 by one-step electrodeposition for corrosion protection in NaCl

Controlling the corrosion rate of magnesium alloys is the critical way to demonstrate their excellent performance in the practical application, it is imperative to design and construct a surface to allow better expeditions adaptation to the application environment. A hydrophobic coating with a good adhesion to the substrate is required. In this study, calcium myristate coating, cerium myristate coating and calcium/cerium myristate mixed coating were fabricated respectively on the surface of AZ31 magnesium alloy by a one-step electrodeposition. The coating characteristics were studied. The corrosion behavior of the coated samples was investigated and the corrosion mechanism was also discussed. The results showed that all three coatings exhibited hydrophobicity with little difference. The presence of Ce ions in the electrolyte promoted the formation of the corresponding coating, and the Ce coating with cracks had the maximum thickest and a poor adhesion to the substrate The Ca coating and Ca/Ce mixed coating presented a good adhesion to the substrate. Compared with the single myristate coatings, the mixed coating exhibited improved corrosion performance. The EIS evolution reveals that the protection effect of the coatings gradually decreases during the immersion process, which is caused by the formation of porous hydrated coating on the surface.