A ceramic layer was prepared on the surface of Al2O3f/ZL109 composites by means of micro-arc oxidation (MAO) technique. The surface morphology and phase constituent of the ceramic layer were analyzed using scanning electron microscope and X-ray diffraction. The polarization curves of the composites before and after MAO treatment were measured and analyzed. The results showed that after Al2O3f/ZL109 composites were treated using MAO technique in silicate solution, the ceramic layer formed, and it was composed of Al, Si, and mullite phase. Al and Si came from Al alloy matrix of the composites, and the mullite phase formed in process of MAO. Al2O3 fiber in the composites affects the electric conductivity of the composites, the MAO reaction is promoted, and the ceramic layer forming on the composite material side is slightly thicker than that on the Al alloy side. After Al2O3f/ZL109 composites were treated using MAO technique, the corrosion resistance of the composites is significantly improved.
Graphical Abstract
A ceramic layer was prepared on the surface of Al2O3/ZL109 composites by means of micro-arc oxidation (MAO) technique. Al2O3 fibers in the composites affect the electric conductivity of the composites during MAO and inhibit the inward growth of MAO ceramic layer. Therefore, the outward growth speed of the ceramic layer is quicker than the inward growth speed.