SURFACE COATED CEMENTED CARBIDE CUTTING TOOL HAVING HARD COATING LAYER EXHIBITING SUPERIOR CHIPPING RESISTANCE IN HEAVY CUTTING

摘要

PROBLEM TO BE SOLVED: To provide a surface coated cemented carbide cutting tool having a hard coating layer exhibiting excellent chipping resistance in heavy cutting. SOLUTION: In the the surface coated cemented carbide cutting tool, a hard coating layer including a lower layer and an upper layer is formed on the surface of a base made of cemented carbide or cermet by chemical deposition. The lower layer is a Ti compound layer having the total average layer thickness ranging from 0.5 to 15μm, and the upper layer includes an upper inner peripheral layer and an upper outer peripheral layer. The upper inner peripheral layer is a composite oxide layer of Al and Cr, which satisfies a specified composition formula and has the average layer thickness ranging from 0.5 to 13μm. The upper outer peripheral layer is formed of a multi-layer alternately stacking layer, which is formed by stacking a thin layer A having an average layer thickness ranging from 0.1 to 0.8μm and a thin layer B having an average layer thickness ranging from 0.1 to 0.6μm, and has a total average layer thickness ranging from 2 to 10μm. The thin layer A is a chrome oxide (Cr2O3) layer and the thin layer B is a composite oxide layer of Al and Cr satisfying a specified composition formula. COPYRIGHT: (C)2007,JPO&INPIT