Feichi Chen, Xiang Xia, Wei Wang, Xiufang Gong, Xiaohu Yuan, Chunmei Tang, Xia Lou, Zhixing Guo, Longgang Wang, Bin Wu, Yunyi Zhu, Mei Yang
In this study, carbide-metal composite coatings (WC-10Co4Cr) were prepared via high-velocity oxygen-fuel (HVOF) spraying, and the influence of Mo2C addition on the microstructure, mechanical properties, and wear performance was systematically investigated. The results indicate that Mo2C is solid-soluted in WC during the preparation process, which induces lattice distortion. Mo2C addition results in refinement of the grain size of WC particles, homogenization of the binder phase distribution, and reduction of the porosity of the coatings. An appropriate amount of Mo2C addition significantly enhances coating performance. The coating containing 2 wt.% Mo2C exhibited optimal properties. It demonstrated the highest microhardness and the lowest porosity, and wear tests revealed it had the lowest friction coefficient and wear rate at room temperature, which is primarily due to enhanced hardness and density that effectively suppressed abrasive wear. At 400 °C, the coating with 2 wt.% Mo2C addition also showed the most stable and lowest friction coefficient. The generated Mo-containing oxides acts as a solid lubricant, isolating friction surfaces and mitigating both oxidative and adhesive wear. However, excessive Mo2C content leads to an abnormal increase in the volume fraction of the binder phase, accompanied by reduced hardness. This induces a transition of the wear mechanism toward adhesive wear dominance, with complex nonlinear evolution characteristics.