Hydrogen-Free Plasma Nitriding to Enhance Wear and Corrosion Resistance of TiZrAlV Alloy

A hydrogen-free surface nitriding process was proposed to enhance the wear properties of TiZrAlV alloy by using double-glow plasma. The structure, morphology, composition, hardness, tribological behavior and corrosion properties of nitrided TiZrAlV alloy have been systematically characterized. A dense and continuous nitrided layer, with a thickness of 110 mu m, was formed on the surface of TiZrAlV alloy, mainly containing TiN, and Ti2N phases. The surface hardness of nitrided TiZrAlV alloy was 1437HV, which is 4 times higher than that of as-received alloy. The formation of high-hardness nitrides phases results in remarkable amelioration in specific wear rate and wear resistance of TiZrAlV alloy after nitriding. Moreover, the corrosion resistance of nitrided TiZrAlV alloy, measured in 1 M HCl and 3.5 wt.% NaCl solutions, has been significantly increased. The nitriding treatment reduced the relative proportion of the weight loss after being immersed in 2 M HCl solution.