CUTTING TOOL MADE OF SURFACE COATED CERMET WITH HARD COATING LAYER EXHIBITING EXCELLENT WEAR RESISTANCE IN HIGH-SPEED HEAVY CUTTING CONDITION

摘要

PROBLEM TO BE SOLVED: To provide a cutting tool made of surface coated cermet with a hard coating layer exhibiting excellent wear resistance in high-speed heavy cutting conditions.;SOLUTION: The surface coated cutting tool is formed by physical vapor deposition of the hard coating layer comprising a compound nitride layer of Al, Ti and Si, on the surface of a WC group cemented carbide or a carbonitride titanium-based cermet substrate. In the hard coating layer, (a) silicon nitride particles are dispersedly distributed in a solid solution base material composed of a compound nitride of Al and Ti, and the silicon nitride particles have a specific content rate, and (b) the solid solution base material in (a) has component concentration distribution structure wherein Al maximum content points and Ti maximum content points exist in alternate repetition at predetermined spaces along a layer thickness direction and the content rates of Al and Ti continuously change between both points. Further, the Al maximum content point and Ti maximum content point satisfy specific composition formulas respectively, and the spacing of both adjacent maximum content points is 0.01-0.1 μm.;COPYRIGHT: (C)2005,JPO&NCIPI