SURFACE COVERED CEMENTED CARBIDE MADE CUTTING TOOL EXCELLENT IN SURFACE LUBRICITY AGAINST CHIP

摘要

PROBLEM TO BE SOLVED: To provide a surface covered cemented carbide made cutting tool excellent in surface lubricity against chips. SOLUTION: This surface covered cemented carbide made cutting tool made by chemically depositing and/or physically depositing a hard covered layer constituted of a Ti compound layer made of one kind or two kinds or more of a TiC layer, a TiN layer, a TiCN layer, a TiCO layer and a TiCNO layer basically and an Al2O3 layer and/or an Al2O3-ZrO2 mixed layer on a surface of a WC group cemented carbide base body in average layer thickness of 3-30μm is constituted by chemically depositing or physically depositing a Tioxide layer to satisfy 1.2-1.9 at an atom ratio of X against Ti in the case when it has average layer thickness of 0.1-5μm as the extreme surface layer and it is expressed in the compositional formula: TiOX on the surface of the hard covered layer.