METHOD FOR FORMING HARD COVERED LAYER TO DEMONSTRATE EXCELLENT CHIPPING RESISTANCE IN INTERMITTENT DOUBLE CUTTING ON SURFACE OF CUTTING TOOL

摘要

PROBLEM TO BE SOLVED: To provide a method for forming a hard covered layer to demonstrate excellent chipping resistance on a surface of a cutting tool.;SOLUTION: The cutting tool is fitted to a rotary table which is rotated and revolved in an arc ion plating device, the inside of the arc ion plating device is the atmosphere of gaseous nitrogen, arc discharge is generated between a Ti-Y alloy cathode electrode and a metal Ti cathode electrode which are disposed facing each other across a rotary table and anode electrodes which are continuously provided on these cathode electrodes. The hard covered layer formed of a complex nitride of Ti and Y in which points containing maximum Y-composition and points containing no Y-composition are alternately and cyclically present at predetermined intervals along the thickness direction, the points containing maximum Y-composition satisfy the composition formula: (Ti_1-XYX)N (X is 0.05 to 0.15 in terms of the atomic ratio), and the space between the point containing maximum Y-composition and the point containing no Y-composition adjacent to each other is 0.01-0.1 μm, is physically vapor- deposited with the total mean layer thickness of 1 to 15 μm on the surface of the cutting tool.;COPYRIGHT: (C)2003,JPO