Experimental and modeling study on the role of Ar addition to the working gas on the development of intrinsic stress in TiN coatings produced by filtered vacuum-arc plasma

The aim of this work is to study and model the effect of argon addition to the N2 working gas on the intrinsic stress of TiN coatings deposited via rectilinear filtered vacuum arc plasma using substrate pulse bias potential. It was found that produced TiN coatings have a NaCl type cubic structure with the [110] axial texture regardless of the concentration of argon in the gas mixture. With increasing the content of argon in the gas mixture, the level of residual stress increased from 7 GPa up to 10 GPa and the coatings hardness remained at a high level of 27-32 GPa. By mathematical modeling based on the modified Davis model, it was shown that increasing the stress level in the TiN coatings with increasing of argon content was due to the intensification of the bombardment process of the coating surface by the inert gas ions.