Evaluation of hardness and wear resistance of nitride layer on Ti-6Al-4V titanium alloy by tungsten inert gas (TIG) melting process

Tungsten inert gas welding setup has successfully implemented on Ti-6Al-4V alloy for the purpose of improving hardness value and tribological properties. In this study, effect of current and scan speed on the formation of nitride layer and its mechanical properties like as micro-hardness value and wear resistance is investigated. Result reveals that the micro-hardness value of nitrided specimen is 2.5 times of the base hardness value of the substrate. Maximum surface hardness achieved of the nitride layer of Ti-6Al-4V alloy is 958 HV. Wear resistance of nitrided titanium alloy are ten times more than untreated titanium alloy. XRD analysis shows that the phases of titanium nitrides are present on the nitrided layer.