CUTTING TOOL MADE OF SURFACE COATED CEMENTED CARBIDE HAVING COATED LAYER EXHIBITING EXCELLENT CHIPPING RESISTANCE IN HIGH-SPEED CUTTING WORK OF HARD-TO-CUT MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a cutting tool made of surface coated cemented carbide having a coated layer exhibiting excellent chipping resistance in high-speed cutting work of hard-to-cut material.;SOLUTION: In this cutting tool made of surface coated cemented carbide, a hard coated layer formed by following (a) to (c) is formed on the surface of a tungsten carbide-base cemented carbide base body or a titanium carbide nitride-base cermet base body; (a) a lower layer formed of (Ti, Al, B)N layer having an average layer thickness ranging from 1 to 5 μm, in which Al maximum content point and minimum content point alternately exist repeatedly at predetermined intervals in the direction of layer thickness, having a component concentration distribution structure in which Al and Ti contents respectively 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, and the Al maximum and minimum containing points satisfy a specific composition formula, (b) an adhesive bonding layer formed of CrN layer having an average layer thickness ranging from 0.1 to 1.5 μm, and (c) an upper layer formed of Cr dispersed Cr₂O₃ layer having an average layer thickness ranging from 1 to 5 μm, and having the structure in which metal Cr is dispersed and distributed in a base of Cr₂O₃ by 0.1 to 5 atom% at the proportion of occupation in the sum amount with Cr₂O₃.;COPYRIGHT: (C)2007,JPO&INPIT