Preparation Of Fuscous Ceramic Film On The Rare Earth Magnesium Alloy By Micro-Arc Oxidation

In this dissertation, the different color ceramic coatings of the good corrosion resistance were obtained by micro-arc oxidation technology on the SJDM-1 Rare earth magnesium-alloys surface. The ceramic coatings showed different color is due to the type and the proportion of the coloring agents in the film. After SEM, XRD, the coating thickness tester and drop experiment, the salt spray corrosion experiment, the analysis was shown that this ceramic layer was mainly composed of MgO, ZnO, Zr₃O, Mg₂SiO₄ and Mg₁₄(SiO₄)₅O₄ and the oxides of coloring agents, and the higher the density of the film, the better corrosion resistance of the film. In addition, after 96 hours of salt spray corrosion experiment, the rating of corrosion was 10. The corrosion resistan of the rare earth magnesium-alloys after sealing hydrated was not sealed 19 times after micro-arc oxidation, and the cathode material, distance, area on the corrosion resistance of ceramic layer had implications.The main reason of ceramic layer corrosion was point corrosion process of the big cathode small anode that happend on the surface of coatings. Failure electrolyte was because there were complex chemical reactions between the electrolyte and electrolyte, the electrolyte and water and other media (such as air) in the micro-arc oxidation process.