Abstract
Micro-V-groove cutting of cobalt-free tungsten carbide using two types of V-shaped diamond tool is performed using a mist of zinc dialkyl-dithiophosphate (ZnDDP) as a lubricant. The two types of tool tested are 1) monocrystalline diamond and 2) polycrystalline diamond made from diamond crystals approximately 30 nm in size. The geometry of the V-groove cutting process is theoretically investigated and the relationships between V-groove angle, original rake angle, and effective rake angle are clarified. Through the cutting experiments, the effects of diamond types and rake angle on tool wear characteristics are explained. When rake angle is set to 0°, tool chipping occurs frequently for both types of diamond tool, even when ZnDDP is supplied. However, tool wear is minimized at a rake angle of -30° for polycrystalline diamond.
