Surface modification of titanium alloy Ti6Al4V by plasma niobium alloying process

Plasma surface niobium alloying process was applied to Ti6Al4V alloy. The optimum processing condition was investigated. Scratch test proved that the alloyed layer was well integrated with the substrate. The hardness and tribological performance of the modified surface was enhanced obviously and could be further improved by applying carburizing as post treatment. Oxidation kinetics study of the alloyed layer demonstrated that the oxidation resistance of the niobium modified surface was improved at temperatures up to 900 °C. Immersion tests showed that corrosion resistance was improved in H2SO4 solution. These results indicate that plasma surface niobium alloying is an effective way to modify the surface of Ti6Al4V alloy, making it qualified for more demanding working conditions.