Study on Properties of Al2TiO5 Coating on Ti-6Al-4V Titanium Alloy

The Al2TiO5Coating was deposited on Ti-6Al-4V alloy substrate by homemade micro-arc oxidation system. The microstructure of Ti-6Al-4V titanium alloy, the phase of coating, the bonding force of the coating and matrix, sulfuric acid corrosion resistance and high-temperature oxidation resistance were study by inverted microscope model, Xray diffract meter, scanning electron microscopy, the coating adhesion automatic scratch tester, box-type furnace. The results show that the phase of coating is composed of Al2TiO5and Al2SiO5, and Al2TiO5.is the main component, the coating surface consists of discharging pit and flange which are unequal in size, rough and overlap and micro-arc oxidation pit diameter increases with the voltage. When micro-arc oxidation voltage is constant, the longer micro-arc oxidation time, the greater the Ti-6Al-4V alloy coating and the substrate binding force. The corrosion resistance of Ti-6Al-4V alloy was improved in sulfuric acid due to micro-arc oxidation; the sulfuric acid corrosion resistance of the coated samples was improved 11 times when the micro-arc oxidation time increased from 5min to 60min. the high-temperature oxidation resistance of Ti-6Al-4V alloy with micro-arc oxidation coatings is higher than Ti-6Al-4V alloy without micro-arc oxidation coating.