The synergy of V and Si on the microstructure, tribological and oxidation properties of AlCrN based coatings

Abstract More and more attention has been paid to AlCrN coatings with self-lubricating property and high temperature oxidation resistance. In this study, the synergy of V and Si on the microstructure, tribological and oxidation properties of AlCrN coatings is investigated in detail. With V is gradually replaced by Si, coatings' microstructures are transformed from compact columnar to coarse columnar, and a dense fine-grained structure, and finally to a featureless dense structure. When the V content is 10 at.%, the coating is consisted of c-VN and c-Al(Cr)N solid solution phases. As decreasing the ratio of V to Si, there is only a cubic Al-Cr-V-N solid solution phase in Al0.58Cr0.31V0.08Si0.03N coating and the coexistence of c-Al(Cr)N and h-Al(Cr)N phases in Al0.58Cr0.31V0.04Si0.07N coating. The addition of Si can promote the transition from c-Al(Cr)N solid solution to h-Al(Cr)N solid solution, and finally forming a nanocomposite structure composed of h-Al(Cr)N nanocrystalline and α-Si3N4 for Al0.58Cr0.32Si0.1N coating. The performance test results indicate that the Al0.58Cr0.31V0.04Si0.07N coating has the best resistance to plastic deformation, the lowest wear rate of 2.72 × 10−16 m3·N−1·m−1 and the oxidation resistance temperature of 1000 °C attributing to the synergistic effect of V and Si.