Study on Preparation and Properties of Micro-arc Oxidation Film on SiC_p Reinforced Aluminum Matrix Composite

The micro-arc oxidation and pore sealing treatment of SiC_p reinforced aluminum matrix composite was carried out. The thickness, roughness, surface morphology, phase composition and salt spray corrosion resistance of the micro-arc oxidation film were tested. The effects of electrical parameters and sealing treatment on the microscopic morphology and corrosion resistance of the micro-arc oxide film layer were studied. The results show that the MAO coating is mainly composed of α-Al₂O₃ phase and γ-Al₂O₃ phase. When the thickness of the film is 30-40 μm, the roughness can be controlled below 2.12 μm; the electrical parameters with the best roughness are frequency of 1000 Hz, duty cycle of 30% and current density of 1 A/dm~2. Sealing treatment can greatly improve the corrosion resistance of micro-arc oxidation layer of the SiC_p reinforced aluminum matrix composite.