Increasing Wear Resistance of Ti6Al4V Alloy by Cathodic Plasma Electrolytic Nitriding

Abstract

A possibility of increasing wear resistance of Ti6Al4V alloy after cathodic plasma electrolytic nitriding in a solution of ammonium chloride and ammonia is shown. The competing effect of the surface erosion by the actions of discharges and high-temperature oxidation on the morphology and roughness of the surface was revealed. The complex effect of the surface roughness and surface layer hardness on the wear resistance of the titanium alloy was determined. It was found that the greatest decrease in the weight wear by a factor of 2.7 was observed for the sample with the maximum microhardness of the surface layer, reaching 820 HV, and the smallest surface roughness. It was shown that the friction coefficient decreased in proportion to the treatment time when the surface layer had low hardness, favoring the sliding of the counter-body.