Optimization of Preparation Process Parameters for HVOF-Sprayed WC-10Co-4Cr Coatings and Study of Abrasive and Corrosion Performances

To enhance the abrasive wear resistance of mechanical components operating in corrosive environments, this study fabricated WC-10Co-4Cr coatings using high-velocity oxygen-fuel (HVOF) thermal spraying technology. A L9 (34) orthogonal array was designed to optimize four key process parameters (kerosene flow rate, oxygen flow rate, powder feed rate, and spraying distance) at three levels each, aiming for minimal porosity. The phase composition, microstructure, hardness, abrasive wear resistance, and corrosion resistance of the coatings were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), microhardness tester, wet sand rubber wheel abrasion tester, and electrochemical workstation. The results indicated that the optimal parameters were a kerosene flow rate of 0.0073 L/s, oxygen flow rate of 15.33 L/s, powder feed rate of 1 g/s, and spraying distance of 326 mm. The coating prepared under these conditions exhibited high density with a porosity of only 0.32% and a high microhardness of 1281 HV1. Compared to the AISI 1020 steel substrate, the optimized WC-10Co-4Cr coating demonstrated a 122-fold improvement in abrasive wear resistance and a better corrosion resistance, showcasing its excellent overall performance and great potential for wear-resistant surface protection in corrosive environments.