采用超音速火焰喷涂工艺分别制备了WC-12Co、Cr3C2-25NiCr碳化物金属陶瓷涂层, 测定了涂层孔隙率、显微硬度及磨粒磨损过程中涂层的质量损失, 探讨了涂层磨损质量损失与涂层种类及结构的关系, 利用扫描电镜对涂层磨损表面形貌进行了观察, 分析了涂层的磨粒磨损失效机制。结果表明: 制备的Cr3C2-25NiCr、WC-12Co涂层组织致密, 孔隙率分别为1.36%和2.76%, 涂层与基体结合良好, 显微硬度分别为822 HV和1 132 HV, 涂层磨损质量损失与磨损距离呈线性关系, Cr3C2-25NiCr涂层的磨损质量损失约为WC-12Co涂层的3倍; 犁沟切削是涂层磨粒磨损初期的主要特征, 而碳化物颗粒的断裂与剥落则是涂层磨损后期失效的主要原因。

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.