Study on the Friction Performance of Cerium Oxide on Supersonic Flame-Sprayed WC-10Co-4Cr Coating

In order to improve the surface wear resistance of the key parts of agricultural machinery, this article uses 65Mn steel, which is commonly used in agricultural machinery, as the matrix and tungsten carbide-based coating as the basis. In total, two coating materials are selected as WC-10Co-4Cr with and without CeO2 added. The coating was prepared by the supersonic flame spraying process (HVOF), and the tribological characteristics and coating of the three samples of 65Mn, WC-10Co-4Cr, and WC-10Co-4Cr+CeO2 coatings were investigated by the comprehensive material surface performance tester. Layer porosity, microhardness, and X-ray powder diffraction (XRD) phase analysis reveal the modification mechanism of WC-10Co-4Cr coating by rare earth CeO2. The experimental comparison results show that WC-10Co-4Cr is prepared on the 65Mn steel substrate, and the WC-10Co-4Cr+CeO2 coating significantly improves the surface hardness, the coating structure is uniform and dense, and the pores are less. The coating hardness value is relatively high, reaching 1200–1500 HV(N/mm2), and the porosity is less than 1%. When the rare earth cerium oxide is added to WC-10Co-4Cr, the porosity of the coating decreases and the hardness increases. It is proved that rare earth has the modification effect of refining the coating structure. Therefore, adding CeO2 to the WC-10Co-4Cr coating and using the supersonic flame spraying process to prepare the coating can obtain more excellent wear resistance.