| The composite ceramic oxide coatings were prepared on 2A12 alloy by Micro arc oxidation in 40gL Na2SiO3 with optimum Na2WO4 electrolyte added ZrO2 or SiC particles. The morphology and the phase compositions of the film were analyzed by Scanning Election Microscopy (SEM) and X-Ray diffraction (XRD). The contents of element in the film were evaluated by Energy Disperse Spectroscopy (EDS). The thickness of the coatings was measured by the Digital Thickness Meter. Wear resistant and corrosion resistant of oxide films were detected by Friction Wear Test and Salt Spray Corrosion Test. The experimental results show that the coatings were consisted ofγ-Al2O3, AlO and mullite phases without Na2WO4, while the coatings were consisted ofα-Al2O3 and mullite phases with Na2WO4, the ceramic coatings and substrate achieve a good combination of metallurgical. The coatings of ZrO2-Al2O3 in electrolyte of 40g/LNa2SiO3,8g/LNa2WO4 and 18.5g/LZrO2 were constituted byα-Al2O3,t-ZrO2 and m-ZrO2 phases and ZrO2 particles were dispersed inα-Al2O3. The coatings in electrolyte with 12.5g/L SiC were component ofα-Al2O3 and mullite phases while SiC particles were decomposed in the process of oxidation and promote the formation of mullite phase. Ceramic oxidate films had been abrasive to substrate by 1384s under 10N load without Na2WO4. With Na2WO4, the loose layer was worn but the dense layer had good wearing resistance, while friction coefficient significantly increased by 1900s. The friction coefficient of ZrO2-Al2O3 composite coatings was steady at 0.15 under 30N load by 4600s. Increased the load to 40N, the dense layer was still no loss. The ZrO2-Al2O3 composite coatings had good corrosion resistance after 170h Salt Spray Corrosion Test. The friction coefficient of coatings added SiC was steady at 0.15 under 30N load by 4900s. Increased the load to 40N, the surface of the coatings had no large piece of debris. The edge of millipore emergence flocculation but deep holes had no change.
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