(TIALV)N(1-X)THIN FILMS DEPOSITED BY REACTIVE SPUTTERING - CHEMICAL-COMPOSITION

The microstructure and chemical composition of sputtered thin films ar e strongly correlated with the deposition conditions. In the present w ork, we report the investigation of the film composition by electron p robe microanalysis and photoemission experiments. These analyses demon strate the progressive nitridation of the films, which change from tet ragonal-like Ti2N to f.c.c.-like TiN phases, by increasing the nitroge n partial pressure in the reactive plasma. The electron spectroscopy f or chemical analysis measurements also show that the surface of the sp uttered films consists of two layers: a bulk material and an altered t ransition layer with TiO(x), Al2O3 and VO(x) oxides as the top layer. The bonding in the nitride transition layer is weaker than that in the bulk material, because of surface oxidation (oxynitrides). Our result s demonstrate that hard coatings with microhardness values higher than 5600 kg mm-2 Hv0.5 can be deposited from Ti-6wt.% Al-4wt.%V targets.