| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool provided with a hard coated layer demonstrating superior chipping resistance and toughness during dry intermittent heavy cutting in which heavy load acts on the cutting blade. SOLUTION: In this surface-coated cutting tool, the hard coated layer formed of a TiN layer is formed on the surface of the base of a cutting tool made of a cemented carbide sintered body by physical vapor deposition. The TiN crystal grains are formed in a columnar crystal structure having a height equal to the average thickness of the layer. When the crystal grain structure of the TiN layer in the horizontal cross section is observed, the area of the TiN layer in the horizontal cross section which is occupied by the crystal grains of 10-100 nm in grain diameter is 90% or higher of the measured area. When the crystal orientation of the crystal grains on the surface of the crystal grain structure is measured by an electron beam back scattering diffracting device, the area of the surface occupied by the division of 0.2-4μm in diameter which is surrounded by a crystal interface at which the difference in crystal orientation between the measurement point and the adjacent measurement point is 15°or larger is 20% or higher of all the area measured. Consequently, superior chipping resistance and toughness can be demonstrated during intermittent heavy cutting. COPYRIGHT: (C)2011,JPO&INPIT
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