CUTTING TOOL MADE OF SURFACE-COATED TUNGSTEN CARBIDE GROUPED HARD METAL WHEREIN HARD COATING LAYER HAS EXCELLENT THERMAL SHOCK RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a cutting tool made of surface-coated hard metal wherein a hard coating layer has excellent thermal shock resistance. ;SOLUTION: An Al₂O₃ layer is given an average layer thickness of 1 to 15μm and an upper part of the Al₂O₃ layer is caused to contain Si at a rate of 1 to 20weight% so as to cover a layer thickness range equivalent to 10 to 70% of the average layer thickness of the Al₂O₃ layer, in the case of a cutting tool made of surface-coated hard metal comprizing a hard coating layer which is formed, over a surface of a hard metal base body, so as to have an average layer thickness of 5 to 20μm and composed of a Ti-compound layer constituting of a single layer of one kind or a plurality of layers of more than two kinds among TiC, TiN, TiCN, TiCO, TiNO, and TiCNO, and an Al₂O₃ layer.;COPYRIGHT: (C)1997,JPO