SURFACE-COATED CEMENTED CARBIDE DRILL WITH SURFACE COATING LAYER COMPOSED OF SUPER-FINE GRAIN ORGANIZATION AND CEMENTED CARBIDE SPUTTER DEPOSITION FILM HAVING EXCELLENT ADHESION PROPERTY

摘要

PROBLEM TO BE SOLVED: To provide a surface-coated cemented carbide drill with a surface coating layer composed of a super-fine grain organization and a cemented carbide sputter deposition film having an excellent adhesion property. SOLUTION: This surface-coated cemented carbide drill comprises a drill body comprising a shank part, and a groove forming part having a cutting blade surface at a tip surface and an outer diameter of 4-16 mm, and composed of a sintered body of tungsten carbide-based cemented carbide including Co by 5-16 wt.% as a coupling phase forming component, and a surface coating layer comprising tungsten carbide-based cemented carbide including Co by 1-4 wt.% as a coupling phase forming component, and composed of a cemented carbide sputter deposition film having a super-fine grain organization is formed at an average thickness of 1-10μm at least on the surface of the groove forming part of the drill body.