CUTTING TOOL MADE OF SURFACE COATED CUBIC BORON NITRIDE BASED SINTERED MATERIAL HAVING HARD COATING LAYER WITH EXCELLENT ABRASION RESISTANCE IN HIGH SPEED CUTTING

摘要

PROBLEM TO BE SOLVED: To provide a cutting tool made of a surface coated cubic boron nitride based sintered material having a hard coating layer with an excellent abrasion resistance in high speed cutting. SOLUTION: The cutting tool is composed of a hard coating layer of a surface coated sintered cemented carbide cutting tool in which a surface of a substrate made of the cubic boron nitride based sintered material is coated with a hard coating layer consisting of a composite nitride of Al and Ti in a whole average thickness of 0.5-10μm by physical vapor deposition. The hard coating layer has the highest Al containing points and the lowest Al containing points alternately and repeatedly with a predetermined interval along the layer thickness direction, and a constituent concentration distribution structure that Al (Ti) content changes continuously from the highest Al content point to the lowest Al content point, or from the lowest Al content point to the highest Al content point. Furthermore, the highest Al content point satisfies a composition formula: (Al1-XTiX)N (where X is 0.05-0.20 by atomic ratio), and the lowest Al content point satisfies a composition formula: (Al1-YTiY)N (where Y is 0.25-0.45 by atomic ratio), and an interval between the highest Al content point and the lowest Al content point adjacent to each other is 0.01-0.1μm. COPYRIGHT: (C)2004,JPO