surface-coated cutting tool the hard coating layer exhibits chipping resistance with excellent high-speed interrupted cutting

摘要

PROBLEM TO BE SOLVED: To provide a surface coated cutting tool having hard coating layer exhibiting excellent chipping resistance in high-speed intermittent cutting.;SOLUTION: The surface of a tool substrate composed of WC base carbide alloy or TiCN base cermet is provided with Ti compound layer as a lower layer (a), and a composite oxide layer of Al, Cr, and Zr as an upper layer (b), which has α-type crystal structure in a chemical vapor deposition state, and satisfies composition formula: (Al_1-Q-RCr_Q Zr_R)₂O₃, wherein Q is 0.005-0.07, R is 0.003-0.05 by atomic ratio. The upper layer composed of the compound oxide layer of Al, Cr, and Zr shows a specific constituent atom sharing lattice point distribution graph obtained by irradiating individual crystal particles having a hexagonal crystal lattice existing in a measuring range of a surface-polished plane with electron beams, measuring a tilt angle formed by the normal lines of face (0001) and face (10-10) as a crystal plane of the crystal particles with respect to the normal line of the surface-polished plane.;COPYRIGHT: (C)2008,JPO&INPIT