SURFACE-COATED CUTTING TOOL

摘要

PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool excellent in wear resistance.SOLUTION: The surface-coated cutting tool is provided in which a hard coating layer having an average layer thickness of 2 to 10μm is formed by vapor deposition on the surface of a tool base composed of tungsten carbide-based cemented carbide. In the surface-coated cutting tool, (a) the hard coating layer is composed of a composite nitride layer of Al and Ti, and a proportion x of Al content to the total amount of Al and Ti is 0.40≤x≤0.75 (atomic ratio), (b) a lattice constant of the composite nitride layer of Al and Ti constituting the hard coating layer assumes a value within the range of -0.057x+4.18 (Å) to -0.057x+4.24 (Å) and (c) a value I(200)/I(111) of the ratio of diffraction peak strength I(200) of (200) plane to diffraction peak strength I(111) of (111) plane of the composite nitride layer of Al and Ti according to X-ray diffraction is 3 or more.