Al_2O_3 coating fabricated on titanium by cathodic microarc electrodeposition

摘要

A Al_2O_3 coating was prepared on titanium substrate by cathodic microarc electrodeposition method in Al(NO_3 )_3 ethanol solution. The coating thickness was about 80 mu m when a 400 V cathodic potential was applied. The morphology and phase constituent of the Al_2O_3 coating were investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD).The isothermal oxidation at 700 deg C and electrochemical corrosion behavior of the coated titanium were analyzed. The coating was composed of gamma-Al_2O_3 and little alpha-Al_2O_3 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.