Microstructural characterization of binary and ternary hard coating systems for wear protection.: Part I:: PVD coatings

Different wear-resistant coatings produced by physical vapour deposition (PVD) were characterized with the aid of cross-sectional transmission electron microscopy (XTEM). All coating systems were optimized by the producers and exhibited good properties with respect to their special applications. The microstructure, texture and chemical composition of binary and ternary systems produced by the are process [TiN, CrN, Cr2N (Ti, Cr)N on steel substrates] and magnetron sputtering process [TiN, CrN on steel substrates, (Ti, Al)N on Si-substrate] were investigated. All coatings had a more or less columnar microstructure, which was interrupted by interlayers in some cases. Whereas are coatings always did show some kind of substrate modification, the latter was not observed after magnetron sputtering. Electron diffraction normally revealed a mono-phase fee structure, except at sites very near to the interface. Only for the systems Cr-N and (Ti, Cr)-N were different additional phases observed at low nitrogen partial pressures. (C) 1999 Elsevier Science S.A. All rights reserved.