Insights into the oxidation resistance mechanism and tribological behaviors of multilayered TiSiN/CrV_xN hard coatings

In the last decades, vanadium alloyed coatings have been introduced as potential candidates for self-lubrication due to their perfect tribological properties. In this work, the influence of V incorporation on the wear performance and oxidation resistance of TiSiN/CrN film coatings deposited by direct current (DC) reactive magnetron sputtering is investigated. The results show that vanadium incorporation significantly decreases the oxidation resistance of the coatings. In general, two layers are formed during the oxidation process: i) Ti(V)O₂ on top, followed by a protective layer, which is subdivided into two layers, Cr₂O₃ and Si–O. ii) The diffusion of V controls the oxidation of V-containing coatings. The addition of vanadium improves the wear resistance of coatings, and the wear rate decreases with increasing V content in the coatings; however, the friction coefficient is independent of the chemical composition of the coatings. The wear of the V-containing coatings is driven by polishing wear.