Properties and Abrasion Mechanism of WC-12Co Coating Prepared by HVOF

In order to improve the anti-abrasion property of the hydraulic machinery surface, conventional WC-12Co coating was prepared by high velacity oxygen fuel (HVOF) with micron powder. The micro-hardness, porosity, bond strength and anti-abrasion performance of the coating were investigated. Phase composition of the coating was characterized by XRD. The microstructure of the coating and the surface morphology of coating after abrasion test were analyzed by SEM. Abrasion failure mechanism in sandy stream was analyzed as well. The results showed that the coating had 0.83% porosity, the average micro-hardness reached 1 189.7 HV0.2 and the bond strength was more than 62 MPa. The anti-abrasion property of the coating was more than 3 times of the matrix, which effectively improved the anti-abrasion performance of the matrix. In the sandy stream, the abrasion was caused by the sand erosion and the cavitation erosion of gas.