Increasing wear resistance of Ti6Al4V alloy by anodic saturation with carbon and nitrogen

Abstract

In this paper, anodic plasma electrolytic nitrocarburising (PEN/C) was applied to Ti6Al4V alloy. This treatment was carried out in electrolyte containing ammonia (5 wt.%), acetone (5 wt.%) and ammonium chloride (10 wt.%) during 5 min at treatment temperature from 750 to 900°C. There were investigated the alloy microhardness, surface roughness and wear resistance. It was shown that the PEN/C results in saturation of studied alloy with oxygen, nitrogen and carbon include formation TiO2 with rutile structure and solid solution in titanium of nitrogen and carbon. This structure provides an increase in microhardness of the surface layer up to 940 HV by sealing the crystal lattice. Surface roughness Ra of treated samples decreases by 1.2–1.4 times and wear resistance increases by 9–10 times after PEN/C. Friction coefficient of PEN/C samples was reduced by 1.5-fold after treatment at 750°C.