High temperature tribological properties of TiAlSiN coatings produced by hybrid PVD technology

TiAlSiN coatings own good oxidation resistance and mechanical properties at high temperature, which are of great importance to the surface protection of high speed machining or hot forming tooling parts. The aim of this study is to investigate the tribological properties at elevated temperature. Results show that a SiO2.nH2O transfer film acts as the lubricant to decrease the friction coefficient at room-temperature. Severe wear was observed due to there is no oxide formed in the operation at 400oC. However, the oxides comprised of Al2O3 and SiO2 formed at 600 °C. Although the friction coefficient of the coatings measured at 600 °C are higher than those measured 400 °C, the wear rates of all samples are lower than those measured at 400 °C. With temperature further increasing, the rutile TiO2 phase could responsible for the lower friction coefficient of all coatings compared with it measured at 600 °C.321