Microstructure and Properties of Ceramic Coatings on 7N01 Aluminum Alloy by Micro-Arc Oxidation

AbstractCeramic oxide coatings were deposited on 7N01 Al alloy by micro-arc oxidation (MAO) in the electrolytic solution. Microstructure, phase composition and wear resistance of the oxide coatings were investigated by SEM, XRD as well as friction and wear test. The micro-hardness and thickness of the oxide coatings were measured. The results showed that the ceramic coating was mainly composed of α-Al2O3 and γ-Al2O3. During oxidation, the temperature in the micro-arc discharge channel was very high to make the local coating molten. From the surface to the interior of the coating, 30∼35μm, micro-hardness of coatings gradually increased, which was about 1300HV0.1. It has been found that the micro-arc oxidation coatings greatly improved the anti-wear properties of aluminum alloys