SURFACE-COATED CERMET CUTTING THROW-AWAY TIP HAVING HARD COATING LAYER EXHIBITING EXCELLENT CHIPPING RESISTANCE IN HIGH SPEED CUTTING OF HIGH HARDNESS STEEL

摘要

PROBLEM TO BE SOLVED: To provide a coated cutting tip having a hard coating layer exhibiting excellent chipping resistance in high speed cutting of high hardness steel.;SOLUTION: One layer of the hard coating layers of the coated cutting tip is constituted of a reformed TiCN layer showing a constituent atom sharing lattice point distribution graph in which a maximum peak exists in Σ3 and a distribution rate occupied in the whole of the Σ3 is ≥60% in a constituent atom sharing lattice point distribution graph prepared based on a measured inclined angle obtained by irradiating each of crystal grains existing in a measuring range of a surface polishing surface with an electron beam by using a field emission scanning electronic microscope and measuring an inclined angle made by normals of a (001) surface and a (011) surface to be crystal faces of the crystal grains in relation to a normal of the surface polishing surface. The surface of the Al₂O₃ layer is polished to have the surface roughness Ra: ≤0.2μm, and a hard coating layer residual stress reduction pattern is formed by laser beam irradiation on the polishing surface.;COPYRIGHT: (C)2007,JPO&INPIT