Al2O3 coating fabricated on titanium by cathodic microarc electrodeposition

A Al2O3 coating was prepared on titanium substrate by cathodic microarc electrodeposition method in Al(NO3)3 ethanol solution. The coating thickness was about 80 μm when a 400 V cathodic potential was applied. The morphology and phase constituent of the Al2O3 coating were investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). The isothermal oxidation at 700 °C and electrochemical corrosion behavior of the coated titanium were analyzed. The coating was composed of γ-Al2O3 and little α-Al2O3 phases. The oxidation resistance of the titanium subjected to cathodic microarc treatment was obviously improved. The polarization test indicated that the coated titanium has better corrosion resistance.