The relationship between residual stress and process parameters in TiN coatings on copper alloy substrates

The goal of this study was the determination of the residual macroscopic stresses in titanium nitride (TiN) coatings deposited by DC planar magnetron sputtering (DCPMS) on a ternary copper alloy (Cu–3% Ti–1% Cr) under different conditions of applied current intensity, Ar/N2 flow ratio and bias voltage. The residual stresses were measured by X-ray diffraction (XRD) with a grazing technique for films of 1 μm thickness. These stresses are mainly due to a growth intrinsic stress. The total stresses have a small contribution of thermal stress, which is not important at the process temperature, in comparison with intrinsic stress. The residual stresses that were obtained are in traction or compression depending on the process parameters used during deposition. These results are analysed with respect to the measures obtained for lattice parameter free of deformation, grain size (GS), adhesion of the coat on the substrate, microhardness and chemical composition of the coating, trying to obtain a relation of the stress evolution with these process parameters.