(Ti,Cr)N and Ti TiN PVD coatings on 304 stainless steel substrates: Texture and residual stress

Growth texture and residual stress were determined by X-ray Diffraction (XRD) methods in three different nitride coating systems (TiN or (Ti,Cr)N single-layers and TiN/Ti two-layers) deposited by reactive sputtering on AISI 304 stainless steel. All samples exhibited the fibre texture typical of many PVD layers grown under non-epitaxial conditions, and the nitride layer had the well-known fee structure of delta-TiN. The main growth direction in TW coatings (independently of the presence of the Ti buffer) was [111], even if a secondary [211] grain fraction was produced by a twin growth mechanism that partially relaxed the intense compressive stress (approximate to-8 GPa). The Ti buffer layer, also in a compressive state, contributed to a further reduction of the in-plane compression in the TiN top coat. The residual stress in the (Ti,Cr)N coatings was very high (approximate to-17 GPa), probably due to the different growth texture (nearly [h00]) and the absence of suitable stress relaxation mechanisms. (C) 1999 Elsevier Science S.A. All rights reserved.