Study on High Temperature Performance of Magnetron Sputtered CrAlSiN Film

Abstract

In order to investigate the high temperature oxidation behaviour of high-speed steel during high speed cutting， a CrAlSiN hard film was deposited on the surface of high-speed steel by magnetron sputtering， and a high-temperature oxidation test was carried out on it at temperatures of 700，800，900，1 000 ℃with a holding time of 1 h. Additionally， the microstructure， nano hardness and modulus， wear rate and oxidation resistance of the film were characterized and analyzed by X-ray diffractometer， scanning electron microscope， energy dispersive spectrometer and nanoindentor. Results showed that the CrAlSiN film had a fcc-CrN structure， and the nano hardness， modulus and wear rate were 24.87 GPa， 300.51 GPa and 0.024 nm/mN respectively. During the oxidation process， when the temperature for high temperature oxidation was 700 ℃，microcracks formed on the surface of the film and an oxide layer composed of Cr2O3 and Al2O3 took shape；at 800 ℃，a small amount of fine white granular oxide appeared； at 900 ℃， microcracks grew， the number of oxides increased， and new Cr2O3 diffraction peaks appeared； at 1 000 ℃， the element diffusion was intense， however no matrix elements diffused onto the surface of the film， indicating that the film still had good oxidation resistance. In general， with the increase of oxidation temperature， cracks and oxides appeared on the surface of the film， which reduced the nano hardness and modulus of the film and increased the wear rate.

Keywords

• magnetron sputtering|cralsin film|oxidation resistance|wear rate