SURFACE-COVERED CEMENTED CARBIDE CUTTING TOOL WHOSE HARD COVERING LAYER EXHIBITS GOOD WEAR RESISTANCE IN HIGH-SPEED HEAVY CUTTING CONDITION

摘要

PROBLEM TO BE SOLVED: To provide a surface-covered cemented carbide cutting tool whose hard covering layer exhibits good wear resistance in a high-speed heavy cutting condition.;SOLUTION: In this surface-covered cemented carbide cutting tool having a hard covering layer made of a compound carbon nitride layer of Zr and Ti on a surface of a cemented carbide substrate with an average layer thickness of 1 to 15 μm, the hard covering layer is formed in a manner that the maximum containing point of Zr and the maximum containing point of Ti are present alternately and repeatedly at a predetermined interval and that the layer has structure of component concentration distribution where the amount of Zr and Ti respectively change successively between the containing points, where the maximum containing point of Zr meeting the composition formula: (Zr_1-xTi_x)C_1-zN_z (at an atomic ratio, X:0.02 to 0.20, Z: 0.40 to 0.60), the maximum containing point of Ti meeting the composition formula: (Ti_1-YZr_Y)C_1-ZN_Z (at an atomic ratio, Y:0.02 to 0.20, Z: 0.40 to 0.60) and the gap between the adjacent points is 0.01 to 0.2μm.;COPYRIGHT: (C)2004,JPO