Microstructure and wear resistance of WC/Co-based coating on copper by plasma cladding

Abstract

The evolution of microstructure and wear resistance of Co-based alloy coating reinforced with WC phase prepared on copper substrate by plasma cladding were investigated. As the WC contents increased, several carbide phases appeared in the coating, the shape of these carbide phases grew from punctate and flower to block and dendrite. The proportion of these carbide phases such as M3W3C and M6W6C in the coating increased, which caused the average hardness to improve from 553.43 HV0.1 to 954.64 HV0.1. Compared with pure cobalt-based alloy coating, WC/cobalt-based coating had a higher oxidation degree and forms CoWO4 phase. The Co-based coating with 40% WC exhibited relatively good wear resistance at room temperature, 400 °C and 500 °C. At 600 °C, the sample with 10% WC possessed the lowest wear weight loss.