Surface-coated cemented carbide gear cutting tool to demonstrate the wear resistance of hard coating layer is excellent in high speed gear cutting of alloy steel

摘要

PROBLEM TO BE SOLVED: To provide a gear cutting tool made of surface coated cemented carbide having a hard coated layer exhibiting excellent wear resistance in high-speed gear cutting of alloy steel.;SOLUTION: In the gear cutting tool made of surface coated cemented carbide, a hard coated layer including an upper layer and a lower layer is formed on the surface of a tungsten carbide-base cemented carbide-made gear cutting tool base body by deposition, wherein (a) the upper layer and the lower layer are both formed of (Ti, Al, Cr)N, the upper layer has an average layer thickness ranging from 0.5 to 1.5 μm and the lower layer has an average layer thickness ranging from 2 to 6 μm, (b) the upper layer has an alternately stacking layer structure of a thin layer A and a thin layer B respectively having an average layer thickness of 5 to 20 nm per layer, the thin layer A is formed of (Ti, Al, Cr)N layer satisfying a composition formula [Ti_1-(A+B)Al_ACr_B]N, the thin layer B is formed of (Ti, Al, Cr)N layer satisfying a composition formula: [Ti_1-(C+D)Al_CCr_D]N, and (c) the lower layer is formed of (Ti, Al, Cr) N layer having a single phase structure and satisfying a composition formula [Ti_1-(E+F)Al_ECr_F]N.;COPYRIGHT: (C)2007,JPO&INPIT