SURFACE COATED CEMENTED CARBIDE CUTTING TOOL HAVING HARD SURFACE COATING LAYER WHICH IS EXCELLENT IN CHIPPING RESISTANCE UNDER HEAVY CUTTING CONDITION

摘要

PROBLEM TO BE SOLVED: To provide a surface coated cemented carbide cutting tool having a hard coating layer which is excellent in chipping resistance under heavy cutting conditions. SOLUTION: The surface coated cemented carbide cutting tool is made by carrying out the physical vapor deposition of a hard coating layer composed of a composite oxide layer of Al and Cr on the surface of a base body composed of tungsten carbide base cemented carbide or titanium carbonitride series cermet having the average layer thickness of 1 to 10μm. The hard coating layer is composed such that the highest Al content point and the highest Cr content point alternately and repeatedly are located at specified intervals in the direction of the layer thickness, and the component density is distributed such that the content ratio of Al and Cr continuously varies in the range from the highest Al contest point to the highest Cr content point respectively, and further, the highest Al content point satisfies the following composition formula, (Al1-XCrX)2O3, (where X is 0.10 to 0.30 in atomic ratio), and the highest Cr content point satisfies the following composition formula, (Cr1-YAlY)2O3, (where Y is 0.05 to 0.25 in atomic ratio), and the distance between the neighboring highest Al content point and the highest Cr content point is 0.01 to 0.1μm. COPYRIGHT: (C)2005,JPO&NCIPI