Abstract:Ceramic coatings were prepared on 2195 Al?Li alloy by micro-arc oxidation (MAO) in a silicate-phosphate electrolyte solution under different current densities. The effect of current density varying from 2 to 8 A/dm2 on the microstructure, corrosion and wear behavior of the coatings were investigated. The surface and cross-sectional morphologies, composition and roughness of the MAO coatings were analyzed by scanning electron microscope (SEM), energy spectrometer (EDS), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and surface roughness meter. The results show that with the increase of current density, the roughness and thickness of the MAO coating increase. The MAO coatings are mainly composed of γ-Al2O3 and a small amount of α-Al2O3. The MAO coatings prepared under the maximum current density is densest. Potentiodynamic polarization tests indicate that the corrosion resistance of coatings increase with the current density. When the current density is 8 A/dm2, the MAO coating exhibits the best corrosion resistance, with a corrosion potential of -0.536 V and a corrosion current density of 4.32×10?? A/cm2, which is two orders of magnitude lower than that of the substrate. Electrochemical Impedance Spectroscopy (EIS) results indicate that, at a current density of 8 A/dm2, the sample possesses the largest capacitive arc radius and the highest impedance magnitude in the low-frequency region.The wear resistance of the MAO coatings increases with the current density. When the current density is 2 A/dm2, the wear mechanism Mainly dominated by abrasive wear. Further increasing the current density, the wear mechanism transformed to abrasive wear. The MAO coatings prepared at 8 A/dm2 show the best wear resistance with a wear rate of 0.1355×10-3 mm3/N·m.