SURFACE COATED CERMET MADE CUTTING TOOL WITH HARD COAT LAYER HAVING EXCELLENT THERMAL IMPACT RESISTANCE AND SURFACE LUBRICITY

摘要

PROBLEM TO BE SOLVED: To provide a surface coated cermet made cutting tool with a hard coat layer having excellent thermal impact resistance. SOLUTION: The cutting tool has a hard coat layer on a surface of a tool base body constituted of WC base cemented carbide alloy or TiCN base cermet. The hard coat layer is constituted of the following (a) to (e) layers: (a) a Ti compound layer composed of one or more layers with a total average layer thickness of 3-20μm as a lower layer, (b) a heat transformedαtype Al2O3layer as an upper layer having a specified crystalline structure and dispersedly distributed cracks generated through a heat transformation and an average layer thickness of 1-15μm, (c) a TiN layer formed by chemical deposition as a surface substrate layer and having an average layer thickness of 0.1-2μm, (d) a Ti oxide layer formed by chemical deposition as a surface layer and having a specified composition ratio and an average layer thickness of 0.1-5μm, and (e) a TiN layer formed by chemical deposition as a color identification layer and having an average layer thickness of 0.05-2μm. COPYRIGHT: (C)2004,JPO&NCIPI