Technical Optimization and Corrosion Resistance of Plasma Electrolytic Oxidation Films

The orthogonal design was used to select the optimal plasma electrolytic oxidation process parameters.The micorstructure and composition of the films prepared under the optimization conditions were investigated.The dropping corrosion test,potentiodynamic polarization curves,cyclic voltammetry curves,EIS and immersion corrosion measurements were employed to evaluate the corrosion resistance of AZ31 magnesium alloy and plasma electrolytic oxidation films.The results showed that the optimal parameters of plasma electrolytic oxidation were 4 g/L KOH,20 g/L silicate,300 V,30 minutes.The ceramic oxide films were composed of MgSiO3 and MgSiO4,and the microhardness,dropping corrosion resistance,uniform corrosion resistance and pitting corrosion resistance could be enhanced considerably.