Study on Factors Affecting the Properties of Micro-arc Oxidation Film on Magnesium Alloys Based on Phosphate Electrolyte

Abstract

In this paper, a single-factor experimental scheme was applied in the phosphate electrolyte system to study the factors affecting the properties of micro-arc oxidation film. First of all, the micro-arc oxidation film on magnesium alloys was prepared by changing the concentration of sodium phosphate, adding sodium carbonate, and changing the voltage and other factors, and then the effects of different factors on properties of the micro-arc oxidation film on magnesium alloys were compared through comprehensive analysis of the electrochemical corrosion test, friction and wear test and scanning electron microscope test. The results showed that in the basic solution of sodium phosphate and potassium hydroxide, the micro-arc oxidation film formed by the introduction of a certain amount of sodium carbonate was uniform, where there were fine cracks and pores on the surface, the porosity increased, and the corrosion resistance and wear resistance of the film were not improved much. When the concentration of sodium phosphate was too high, the formed micro-arc oxidation film was not uniform, the surface roughness increased, and the corrosion resistance and wear resistance decreased. When the voltage was increased moderately, the formed micro-arc oxidation film was smooth and uniform, whose corrosion resistance and wear resistance were effectively improved, and the time of micro-arc oxidation was shortened.