SURFACE COATED CUTTING TOOL WITH HARD COATING LAYER EXHIBITING SUPERIOR CHIPPING RESISTANCE AND WEAR RESISTANCE IN HIGH-SPEED INTERMITTENT CUTTING

摘要

PROBLEM TO BE SOLVED: To provide a surface coated cutting tool with a hard coating layer exhibiting superior chipping resistance and wear resistance in high-speed intermittent cutting.SOLUTION: The surface coated cutting tool has a Ti compound layer and an AlOlayer coated and formed on the surface of a base. In a crystal grain of the AlOlayer, when finding an inclination angle frequency distribution by measuring an inclination angle made by the normal of (0001) face with respect to the normal of a base surface, peaks with peak strength of I, Iare present respectively, in an inclination angle section within a range of 0 degree or more and less than 5 degrees, and in an inclination angle section within a range of 5 degrees or more and less than 10 degrees. A value I/Iof the ratio of the peak strength satisfies 1I/I3, and the frequency ratios existing in the respective inclination angle section are 45-70% and 15-40%. In addition, in between crystal grains adjacent to each other, a crystal grain boundary ratio in which an angular difference formed by the normal of the (0001) face is 5 degrees or less is 80% or more, and a crystal grain boundary ratio in which an angular difference formed by the normals of the (10-10) faces is 5-30 degrees is 80% or more.