| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool with a hard coating layer exercising superior chipping resistance in heavy cutting. SOLUTION: The hard coating layer is composed of a composite nitride layer of Al and Cr satisfying a composition formula (Cr<SB>1</SB>-xAl<SB>x</SB>)N (X is 0.40-0.70 by atomic ratio) on a cutting tool substrate surface comprising cemented carbide, cermet, and a cubic boron nitride-based ultra high pressure sintered body. When a crystal orientation analysis by EBSD is carried out in regard to the composite nitride layer, an area portion of crystal grains having a crystal orientation of 111 within a range of 0-15 degrees from a normal direction of a surface polishing surface is 50% or more. The composite nitride layer of Al and Cr indicates such a crystal arrangement that the portion of the small angle grain boundary (0<θ≤15°) is 50% or more when the angle of the adjacent crystal grains is measured. COPYRIGHT: (C)2009,JPO&INPIT
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