Study on Wear Behaviors and Grain Effects of PCD Cutting Tools in Turning Granite

In this paper, three types of polycrystalline diamond (PCD) tools marked as PCD 030, PCD 010 and PCD 005 (equivalent to 30, 10, and 5μm average grain size of original diamond) were tested, and their wear behaviors was studied. The wear of PCD cutting tools in machining granite bars was invested by a turning process. The experiments were carried out under wet condition. Wear volume was measured by optical microscopy and wear morphology was examined by scanning election microscopy (SEM) and optical microscopy. By comparing the flank face, the experiments results show that the PCD tools with coarse original diamond grain size have long life at three cutting speeds, and the tool life of the three PCD tools decreases with the increase of cutting speed. SEM morphology by secondary electron image analysis indicates that the dominant wear mechanism for PCD 010 and PCD 005 is abrasive wear. While for PCD 030, the abrasive wear mechanism is predominant wear in the machining, occasionally some cleavage wear are also observed.