SURFACE-COATED CUTTING TOOL WITH HARD COATED LAYER EXERTING EXCELLENT WEAR RESISTANCE AND CHIPPING RESISTANCE IN HIGH-SPEED CUTTING WORKING

摘要

PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool having excellent chipping resistance and wear resistance.;SOLUTION: On the surface of a tool base body, (a) an AlTi composite nitride layer which has a lamination or alternate lamination structure of a thin layer A and a thin layer B and has the sum average film thickness of 1 to 10 μm is provided, (b) the thin layer A is constituted with only crystal grains having an Al content proportion of 0.65 to 0.75 (therein, atomic ratio) and a particle size of 0.05 μm or less, on a region within 100 μm from the ridge line part of the intersection of the flank and rake face, (c) the thin layer B has an Al content proportion of 0.50 to 0.60 (therein, atomic ratio), has a grain size length proportion of crystal of grain size 1.0 μm or more, occupied by 50 to 90% on a region within 20 μm from the ridge line part of the intersection of the flank and rake face, and has a grain size length proportion of crystal of grain size 1.0 μm or more, occupied by less than 50% on a region beyond 20 μm and of 100 μm or less from the ridge line part of the intersection of flank and rake face and (d) the thin layer A is mixed crystal of cubic crystal and hexagonal crystal and the thin layer B is single crystal of the cubic crystal.;COPYRIGHT: (C)2015,JPO&INPIT