Microstructure and Tensile Fracture Mechanism of WC-10Co-4Cr Coating Prepared by High Enthalpy Plasma Spraying

WC-10Co-4Cr coating was prepared on the surface of 0Cr13Ni4Mo stainless steel by SQC-100 high enthalpy plasma spray system. The porosity, microhardness, wear resistance, bonding strength of the WC-10Co-4Cr coating were assessed in terms of metallographic testing, friction and wear testing, bonding strength testing and tensile testing. The microstructure of the coating was observed by scanning electron microscopy (SEM), and the composition of the coating was analyzed by X-ray diffraction (XRD). The results show that the porosity of the WC-10Co-4Cr coating was 0.77%, the hardness was 1 210 HV, and the anti-wear property of the coating was 143 times more than that of the stainless steel matrix. The coating had good bonding to the matrix, with a bonding strength of 72 MPa. The WC-10Co-4Cr coating with dense structure was mainly composed of WC phase and few W₂C phase, and the fracture mechanism was transgranular fracture and intergranular fracture. Increasing particle speed and temperature can improve the binding strength of the WC-10Co-4Cro coating.