Mechanical and corrosion-resistant coatings prepared on AZ63 Mg alloy by plasma electrolytic oxidation

Using the plasma electrolytic oxidation (PEO) process conducted in galvanostatic mode at a constant current density of 0.2 A/cm2 in aqueous aluminate, silicate, and phosphate electrolytic solutions, we successfully produced magnesium oxide coatings (up to 182 mu m) on AZ63 alloy. Structural, chemical composition, and morphological evaluations of the coatings were investigated by XRD, XPS, and SEM. The results indicated that mixed-crystalline magnesium oxide grown on pure AZ63 alloy forms porous 8-30 mu m PEO layers with increased hardness and improved corrosion resistance. At the same time, values of 26.9 GPa and 2.0 mu A/cm2 yield noticeable performance characteristics.