Tribological behaviour of CrAlN coatings at 600°C

Chromium aluminium nitride (CrAlN) coatings were prepared by a modified ion beam enhanced magnetron sputtering system in this study. Friction and wear tests were carried out by a (pin on disc) tribometer with Si₃N₄ (at 600°C) balls as a counter material without lubricant. The results show that CrAlN coating deposited at −120 V has a higher Al content and is more resistant to high temperatures than that deposited at 0 V. During the wear test at 600°C, the friction coefficient of CrAlN coating deposited at −120 V is higher than that of CrAlN coating deposited at 0 V, but the increased hardness, fracture toughness and improved microstructure in CrAlN coating deposited at −120 V can be attributed to its increased wear resistance and its wear rate is nearly unchanged. The wear resistance of the CrAlN coated H13 steel specimen has been greatly improved compared to the uncoated reference H13 steel specimen.