中文摘要：

用三种不同晶粒尺寸的自制PCD刀具，在三种切削速度下进行了花岗岩的湿式连续切削试验。对刀具前、后刀面的显微形貌特征进行了观测，分析了刀具失效机理，比较了不同晶粒尺寸及不同切削条件下刀具的切削寿命。对刀具后刀面磨损的测量结果表明，在三种切削速度下，粗颗粒PCD刀具显示出更长的刀具寿命；随着切削速度的增加，三种刀具的寿命都有所下降。SEM二次电子图像显示，PCD010和PCD005刀具的磨损机制为硬质点的机械磨损，而晶粒较粗的PCD030刀具的主要磨损机制为机械磨损，同时伴有穿晶磨损。

英文摘要：

Using three kinds of PCD cutting tools with different grain sizes, a continuous wet cutting examination for granite was carried out under different cutting speeds. The micro-topographies on rake face and flank of PCD tools were observed, the failure mechanisms of these tools were analyzed, and the life-spans of tools with different grain sizes were compared under different cutting speeds. Measuring results of wear on tool flank show that under different cutting speeds, the PCD tool with coarse grains has longer life-span, and life-spans of three kinds of PCD tools decreased as cutting speed in- creased. SEM images show that the wear mechanisms of PCD010 and PCD005 tools are mechanical wear of hard particles, and the main wear mechanism of coarse-grained PCD030 tool is mechanical wear, while accompanied with transcrystalline wear.