Enhancement of Wear and Corrosion Resistance of Ti6Al4V Alloy through Hollow Cathode Discharge-Assisted Plasma Nitriding.

In order to improve the wear and corrosion resistance of Ti6Al4V alloy, a Ti-N compound layer was formed on the alloy by plasma nitriding at a relatively low temperature (750 °C) and within an economical processing duration (4 h), in a mixture of NH and N gases with varying ratios. The influence of the gas mixture on the microstructure, phase composition, and properties of the Ti-N layer was investigated. The results indicated that the thickness of the nitrided layer achieved in a mixed atmosphere with optimal proportions of NH and N (with a ratio of 1:2) was substantially greater than that obtained in an atmosphere of pure NH. This suggests that appropriately increasing the proportion of N in the nitriding atmosphere is beneficial for the growth of the nitrided layer. The experiments demonstrated that the formation of the surface nitrided layer significantly enhances the corrosion and wear resistance of the titanium alloys.