| Micro-arc oxidation is widely recognized as an ideal surface treatment technology to magnesium alloy. This method employs electrochemical oxidation combined with high voltage spark discharge treatment producing a dense ceramic coating. The coating has the following advantages:high adhesive strength with the substrate, easily controlled thickness and no need to the size or the shape to the samples. In addition, through the process, the wear and corrosion resistance, thermal shock resistance, and the insulation property can be largely improved. Thus, to investigate the parameters in order to fabricate the useful coating is necessary. In this paper, the growth mechanism and the property of corrosion resistance are studied.In the preparation and fabrication, Orthogonal experimental method was used to optimize the mass ratio, based on this, the voltage, temperature and the oxidation time were fixed. The effect of concentration of the solution-KF,KOH and NaAlO2 on the thickness is mainly discussed. Scanning electrical microscope(SEM),X-ray diffraction(XRD), and the Vortex Thickness tester were use to detect the structure and constitution. It is found that the coating have many micro pores. Some volcanic structure can be found. The chemical phases are Mg,MgF,MgO,MgAlO2.About the other properties experiments, the Scratching Tester was used to test the adhesive strength. The Interfacial adhesion appears a good outcome. NaCl solution immersion experiments were used to test of the micro-arc oxidation coating corrosion resistance. And the micro-arc oxidation film the show a good corrosion resistance. With the thickness increases, the property is getting better. And when the thickness went up to 15μm, it performed the best corrosion resistance.
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