Oxidation resistance of Cr1−XAlXN and Ti1−XAlXN films

Cr1−XAlXN films were synthesized on mirror-polished stainless steel substrates by the arc ion plating method using Cr1−XAlX alloy targets with diffent Al contents. Oxidation resistance of films was estimated by heating substrates in air at 800, 900 and 1000 °C and subsequent analysis by the X-ray diffraction method (XRD). The XRD peaks from Ti0.7Al0.3N films, annealed at 800 °C for 14 h, disappeared and the peaks from iron oxides consequently appeared. The oxidation resistance of Ti1−XAlXN films improved with increasing Al content X. On the other hand, the peaks from Cr1−XAlXN films which were annealed at 800 °C did not change at all, but Cr1−XAlXN films were slightly oxidized over 900 °C. It is considered that the oxidation resistance of Cr1−XAlXN films was superior to that of Ti1−XAlXN films.