Abrasive Wear Performance of HVOF-Sprayed Carbide Cermet Coatings

WC-12Co and Cr3C2-25NiCr carbide cermet coatings were prepared by high velocity oxy-fuel (HVOF) technique. Coating porosity, microhardness and wear mass loss of coating material in the abrasive wear test were studied. The relationship between the wear mass loss and coating type, coating microstructure was analyzed and the abrasive wear mechanism of HVOF sprayed carbide cermet coatings was discussed through observation of the worn morphology of coatings by SEM. The results indicate that Cr3C2-25NiCr and WC-12Co coatings had dense microstructure and good bonding with the matrix, and the porosities were 1.36% and 2.76%, the microhardness value of two coatings was 822 HV and 1 132 HV, respectively. The accumulative wear mass loss and wear distance had a linear relationship and the wear mass loss of Cr3C2-25NiCr was more than three times than that of WC-12Co coating. The cutting or gouging was the main feature of the coatings in the early stage of wear process, however, the cracking and spalling of carbide particles in the coatings were the main reason for the failure of coatings in the latter process.