CUTTING TOOL COATED WITH COMPOSITE HARD LAYER SURFACE

摘要

PURPOSE: To provide a composite hard layer coated cutting tool having a long sevice life. CONSTITUTION: In a cutting tool having the base body surface coated with a composite hard layer composed of a titanium compound inner layer containing at least one layer of titanium carbonitride and an aluminum oxide outer layer, at least one layer of titanium carbonitride constituting the titanium compound inner layer is the titanium carbonitride layer representing the maximum peak on (220) surface by X-ray diffraction. The aluminum oxide outer layer comprising mainlyκ-type crystal is the aluminum oxide layer representing the maximum peak on the surface defined as a surface of 2.79Åsurface gap ofκ-Al2 O3 in ASTM to provide the cutting tool having the surface coated with the composite hard layer and titanium compound inner layer.