CUTTING TOOL MADE OF SURFACE COATED CEMENTED CARBIDE HAVING CUTTING BLADE PART EXHIBITING SUPERIOR HEAT- RESISTING PLASTIC DEFORMATION IN HIGH-SPEED CUTTING

摘要

PROBLEM TO BE SOLVED: To provide a cutting tool made of surface coated cemented carbide having a cutting blade part exhibiting superior heat-resisting plastic deformation in high-speed cutting. SOLUTION: In this cutting tool made of surface coated cemented carbide, a hard coating layer formed by a multiplayer with alternations of a first thin layer and a second thin layer individually having an average layer thickness of 0.01 to 0.1μm is formed on the surface of a tungsten carbide-base cemented carbide substrate with the whole average layer thickness of 0.8 to 10μm by evaporation. The first thin layer is formed of an aluminum oxide layer having aκ-type crystal structure and the second thin layer is formed of a titanium nitride layer. The proportion of the first thin layer occupying the hard coating layer is 60 to 90 mass %.