Ceramic oxide coatings were fabricated on 7075 ultra high strength aluminum alloy by micro-arc oxidation(MAO)for different oxidation time in an alkaline aqueous solution with aluminate.The microstructures were investigated by SEM and XRD,and the effect of different oxidation time on micro hardness,wear and electrochemical properties of the ceramic coatings was examined. The results indicate that the prepared ceramic oxide coatings with thickness of more than 50 μm are compact and combined with the substrate...