CUTTING TOOL MADE OF SURFACE COATED CUBIC BORON NITRIDE GROUP SINTERED MATERIAL WITH HARD COATING LAYER EXHIBITING EXCELLENT CHIPPING RESISTANCE IN HEAVY CUTTING

摘要

PROBLEM TO BE SOLVED: To provide a cutting tool made of a surface coated cubic boron nitride group sintered material with a hard coating layer exhibiting excellent chipping resistance in heavy cutting. SOLUTION: This cutting tool made of the surface coated cubic boron nitride group sintered material is formed by physical vapor deposition of the hard coating layer comprising a compound nitride of Ti, Al and Zr, in the average layer thickness of 0.5-10μm on the surface of a substrate formed of a cubic boron nitride group sintered material. The hard coating layer has a component concentration distribution structure wherein Al maximum content points and Al minimum content points exist in alternate repetition at prescribed spaces along a layer thickness direction, and the content rates of Ti and Al continuously change from the Al maximum content point to the Al minimum content point and from the Al minimum content point to the Al maximum content point. Further, the Al maximum content points satisfy a specific composition formula respectively, and the spacing of the adjacent Al maximum content points and Al minimum content points is 0.01-0.1μm. COPYRIGHT: (C)2005,JPO&NCIPI