The effect of temperature on wear mechanism of the AlCrN coated components

Abstract

The aim of the paper was to investigate the temperature effect on the wear mechanism of AlCrN coated components. The coating was deposited by Physical Vapour Deposition process (PVD) on WC/Co substrate. Tribological tests were performed in sliding conditions using a high temperature T-21 tribotester, produced by ITeE-PIB, Radom. The tests were performed in a ball-ondisc configuration (Si3N4 ceramic ball) under dry friction conditions at room temperature, 600 °C and 750 °C. An optical microscope, interferometer, and scanning electron microscope were used to analyse the worn surfaces. Following this study, it was found that the wear resistance of the coating AlCrN tribosystem depended on the temperature. The most wear was reported at room temperature. At 600 °C, the intensity of wear of the coating was 4-fold lower, and at 750 °C, wear was 6-fold lower than at room temperature. High temperature wear resistance of AlCrN coating involves creating a protective oxide layer. Performed analysis of the structure of the surface layer showed a much higher content of oxygen in wear scar than outside. At high temperatures, friction additionally intensified the oxidation process, thus the amount of oxygen in surface layer increased with temperature. Oxide layer, Al2O3 and Cr2O3 probably created at high temperature was a barrier to further oxidation of the coating and had very high wear resistance at high temperatures.