SURFACE COATED CEMENTED CARBIDE CUTTING TOOL HAVING HARD COATED LAYER EXHIBITING EXCELLENT CHIPPING RESISTANCE UNDER HEAVY CUTTING PROCESSING CONDITIONS

摘要

PROBLEM TO BE SOLVED: To provide a surface coated cemented carbide cutting tool having a hard coated layer exhibiting excellent chipping resistance under heavy cutting processing conditions. SOLUTION: In the surface coated cemented carbide cutting tool, the hard coated layer with an average layer thickness of 1 to 15μm satisfying (a) to (d) is physically deposited on a surface of a cemented carbide body. (a) The hard covering layer has a two-phase structure in which Co is dispersed and distributed into a base of composite nitride of Al and Ti. (b) The base of composite nitride of Al and Ti satisfies a composition formula: (Al1-XTiX)N (where X is 0.35-0.60 by atomic ratio). (c) The layer has a Co component concentration distribution variation structure in which the Co highest ratio dispersion point and a Co absence point alternatively and repeatedly exist at predetermined intervals along the thickness direction and the dispersion ratio of Co is continuously increased and decreased from the Co highest ratio dispersion point to the Co absence point and from the Co absence point to the Co highest ratio dispersion point. (d) The interval between the adjoining Co highest ratio dispersion point and Co absence point is 0.01 to 0.1μm, and the Co dispersion ratio at the Co highest ratio dispersion point is 1 to 10 at.% as the ratio occupied in the total amount with the base. COPYRIGHT: (C)2005,JPO&NCIPI