Surface-coated cutting tool that exhibits chipping resistance the hard coating layer excellent in high speed heavy cutting and wear resistance

摘要

PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool having a hard coating layer exhibiting excellent chipping resistance and wear resistance in high-speed heavy cutting.;SOLUTION: In the surface-coated cutting tool, a hard coating layer comprising a lower layer and an upper layer having an alternately laminated structure of a thin layer A and a thin layer B is vapor-deposition formed on the surface of a tool base. On a tool base surface, (a) as the thin layer A, a composite nitride layer of Al and Cr (and Si) represented by a composition formula: (Al_1-αCr_α)N or (Al_{1-α-β}Cr_αSi_β)N, (b) as the thin layer B, a composite oxide layer of Al and Cr (and Si) represented by a composition formula: (Al_1-YCr_Y)₂O₃ or (Al_1-Y-ZCr_YSi_Z)₂O₃, and (c) as the upper layer, a composite oxide layer of a composition inclination type of Al and Cr (and Si) which is represented by a composition formula: (Al_1-YCr_Y)_1-XO_X or (Al_1-Y-ZCr_YSi_Z)_1-XO_X and in which the O (oxygen)-containing ratio of the upper layer is decreased from the lower layer side toward the upper layer surface, are vapor-deposition formed. Here, the following relations are satisfied: 0.25≤α≤0.45, 0.01≤β≤0.1, 0≤X≤0.2, 0.25≤Y≤0.45 and 0.01≤Z≤0.1 in an atomic ratio.;COPYRIGHT: (C)2011,JPO&INPIT