SURFACE COATED CUTTING TOOL WITH HARD COATING LAYER EXERTING EXCELLENT CHIPPING RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a surface coated cutting tool with a hard coating layer exerting excellent chipping resistance in high speed heavy cutting of a difficult-to-cut material such as stainless steel and tag tile cast iron. SOLUTION: In this surface coated cutting tool, (a) a Ti compound layer as a lower layer, (b) a α type Al2O3layer as an intermediate layer, and (c) a α type Al2O3layer containing Cr having a planar polygon-shaped and vertically long shaped crystal grain structure as an upper layer are formed by vapor deposition on a surface of a tool base body. The intermediate layer and the upper layer are composed of the α type Al2O3layer having a high (0001) plane orientation rate and the α type Al2O3layer containing Cr, respectively. The inside of the crystal grains of ≥60% in area rate, of the crystal grains of the upper layer, is divided by a crystal lattice interface made of an organized atom common lattice-point form expressed by at least one or more of Σ3. COPYRIGHT: (C)2010,JPO&INPIT