SURFACE COATED CEMENTED CARBIDE CUTTING TOOL HAVING HARD COATING LAYER EXHIBITING EXCELLENT WEAR RESISTANCE IN HIGH SPEED CUTTING OF SOFT WORK MATERIAL HARD TO WORK

摘要

PROBLEM TO BE SOLVED: To provide a surface coated cutting tool having a hard coating layer exhibiting excellent wear resistance in high-speed cutting of soft work material hard to work. SOLUTION: In this coated cutting tool, the following hard coating layer is formed on the surface of a cemented carbide base body. The hard coating layer includes: (a) a surface layer formed of a Cr boride layer; and (b) a wear resisting hard layer formed of a compound nitride layer of Ti, Al, Cr and Si, which satisfies a composition formula: (Ti1-(X+Y+Z)AlXCrYSiZ)N (wherein, by atomic ratio, 0.45≤X≤0.65, 0.01≤Y≤0.10, 0.01≤Z≤0.10, 0.50≤X+Y+Z≤0.70 are designated). Further, the surface roughness for at least a cutting face part and a flank part including a cutting blade ridge line part of the surface layer is set to Ra:0.2μm or less by injecting a polishing liquid where aluminum oxide fine grains are mixed as an injection abrasive by wet blast in the state where an abrasive layer formed of a Cr nitride layer is deposited on the whole surface of the surface layer, and polishing in the coexistence of pulverized Cr nitride fine grains obtained by wet blasting the abrasive layer and aluminum oxide fine grains as the injection abrasive. COPYRIGHT: (C)2007,JPO&INPIT