SURFACE-COATED CERMET CUTTING TOOL SUPERIOR IN HIGH SPEED CUTTING AND EXHIBITING HEAT RESISTANT PLASTIC DEFORMABILITY

摘要

PROBLEM TO BE SOLVED: To provide a surface-coated cermet cutting tool superior in high speed cutting, and exhibiting heat resistant plastic deformability.;SOLUTION: This surface-coated cermet cutting tool has a hard coating layer constituted of (a) to (d) on a surface of a cermet base body constituted of tungsten carbide group cemented carbide or titanium carbonitride group cermet. (a) A titanium nitride layer and/or a titanium carbonitride layer chemically evaporated and formed as a close contact backing layer, and having the average layer thickness of 0.1 to 2 μm. (b) A heating transformed α type aluminum oxide layer formed by transforming a crystal structure into an α type crystal structure by applying heat treatment to aluminum oxide having a κ type or θ type crystal structure in a state of being chemically evaporated and formed as a hard abrasion resistant layer, and having a structure of dispersing-distributing a heating transformed crack and the average layer thickness of 5 to 30 μm. (c) An evaporated α type aluminum oxide layer having an α type crystal structure in a state of being chemically evaporated and formed as a surface smoothing layer, and having the average layer thickness of 0.1 to 2 μm. (d) A titanium nitride layer chemically evaporated and formed as a use before-after identification layer when necessary, and having the average layer thickness of 0.1 to 2 μm.;COPYRIGHT: (C)2004,JPO&NCIPI