Microstructure and Wear of Cr/WC- Ni60 Based Composite Coating by Vacuum Sintering

WC-Ni60 composite powders were mixed and deposited on Cr12MoV die steel by vacuum sintering technique. In order to prevent WC powders decomposition at the high temperature, Cr film was coated by D.C. magnetron sputtering and then prepared Cr/WC-Ni60 composite coating. The structure and composition and microhardness were measured by SEM and XRD and hardness tester. Tribological experiments were carried out on an abrasion machine. The results showed that thickness of Cr film is 3~5um. Some WC particles formed hard phases in nickel based solid solution to improve the hardness of the coatings. Due to Cr film preventing WC decomposition, Cr/WC-Ni coating had the higher hardness values compared with WC-Ni60 coating. The coating surface was uniform and compact and had no cracks. During the sliding wear, Cr/WC-Ni coating had a better wear resistance, and mass loss of wear was the least.