| 摘要 |
PROBLEM TO BE SOLVED: To provide a diamond coated hard metal cutting tool which is excellent in an interfacial strength between a diamond film and a tool base body and is excellent in resistance to abnormal damage such as chipping, defect and peeling.SOLUTION: WC particles 4 have an average particle size of 0.5 to 2.5 μm (a), a part of a Co connection phase 5 on a region of 1 to 5 μm depth to an inner part of a tool base body is removed from an interface between a diamond film 1 on a flank surface and the tool base body on the longitudinal cross-section observation vertical to a flank surface of the tool, in the region where the a part of the Co connection phase is removed, the length of a bonded interface 6 between WC particles is 0.20 to 0.60 times of a circumferential length of the WC particles (b), the WC particles are composed of mixed grain of fine grain WC particles having an average particle size of 0.3 to 0.5 μm and coarse grain WC particles having an average particle size of 1.5 to 3.0 μm by means of a grain size distribution measurement device according to a laser diffraction method, and a tungsten carbide base hard metal 3 contains one kind or two kinds of TaC, NbC or CrCby 0.1 to 2.0 mass% as a compound composition total content.SELECTED DRAWING: Figure 2 |
