| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface coating cutting tool whose hard coating layer exerts excellent chipping resistance in high-speed intermittent cutting work of, e.g., alloy steel.SOLUTION: In a surface coating cutting tool, the surface of a substrate consisting a WC-based hard metal, A TiCN-based cermet, and a cBN-based high-pressure sintered body is coated with a (TiAl)(CN) layer, where atomic ratios X and Y meet the conditions 0.60≤X≤0.95 and 0.0005≤Y≤0.005, consisting of a mixed structure of a hexagonal crystal phase and a cubic crystal phase. When the inclination angle of the normal line of the (0001) plane of the hexagonal crystal phase crystal grain to the normal line direction of the surface of the substrate is measured, the maximum peak appears in an inclination angle division ranged from 2 to 12 degrees, and the frequency ratio in the inclination angle division is 40% or higher. More preferably, the average aspect ratio αof the cubic crystal grains is smaller than 2; the average grain width ωof the cubic crystal grains is smaller than 0.3 μm or smaller; the average aspect ratio αof the hexagonal crystal grains is 2 or higher; and the average grain width ωof the hexagonal crystal grains is 0.1-2 μm. |
