Oxidation and diffusion processes during annealing of TiSi(V)N films

The degradation of self-lubricant hard coatings applied in tools for high-speed cutting or dry drilling operations occurs by a combination of wear, oxidation and diffusion. The aim of this investigation was to study the effect of V additions on the diffusion processes and on the oxide scale formation during annealing of TiSiVN coatings. Relation of these results with those achieved for a reference Ti0.80Si0.15N coating with similar Si content is also presented. The structure evolution of the Ti0.65Si0.11V0.15N film was assessed by an in-situ hot-XRD device. A dual layer oxide was formed in the case of Ti0.80Si0.15N coating with a protective Si-O layer at an oxide/coating interface; however, in zones of film defects a complex oxide structure was developed. V additions increased the oxidation rate of the coatings as a result of the V ions diffusion throughout the oxide scale, which inhibited the formation of a continuous protective silicon oxide layer.