Thermal shock resistance of Cr/CrN/Cr/CrAlN multilayer anti-erosion coating

Abstract

In this work, a 12 μm Cr/CrN/Cr/CrAlN erosion-resistant multilayer coating was prepared by arc ion plating. According to the application conditions of high-temperature changing environment, the high-temperature thermal shock performance and erosion resistance of the coating were studied. The results show that the Cr/CrN/Cr/CrAlN coatings show no change after thermal shock up to 700 °C. After thermal shock at 900 °C, the surface shows discolouration and wrinkling, and the nitride phase in the coatings disappears and Cr2O3 and α-Al2O3 phases appear. The hardness of the coating after thermal shock is reduced from 3658.57 Hv to 1930.96 Hv, and the adhesion strength is reduced from HF1 to HF4. The erosion rates of the coatings after thermal shock at room temperature, 300 °C, 500 °C and 700 °C do not vary significantly, and are within 1 mg/g at 30° and 90°. The coating is completely unprotective when the thermal shock temperature reaches 900 °C, reaching 2.731 mg/g at 30° and 4.832 mg/g at 90°. It shows that the coating has an anti-erosion protection effect within 700 °C, but the coating has completely failed after a thermal shock at 900 °C and has no protective effect.