SURFACE COATED CUTTING TOOL

WIPO Patent Application WO/2023/182126

A1

A coated tool in which: a mean thickness At of a lower layer A is 0.3 to 6.0 μm, a mean thickness Bt of an upper layer B is 0.1 to 3.0 μm, and 2.0≤At/Bt≤5.0; the lower layer A comprises alternately stacked layers of an A1α layer having a mean thickness αt and an A1β layer having a mean thickness βt, where 0.5 nm≤αt≤4.0 nm, 0.5 nm≤βt≤4.0 nm, and 0.7≤βt/αt≤1.3; the A1α layer composition is AlxTi1-xN (where an average value of x, xavg, is 0.35≤xavg≤0.55), the A1β layer composition is AlyTi1-yN (where an average value of y, yavg, is 0.60≤yavg≤0.80), and 1.2≤yavg/xavg; and the upper layer B composition is AlaTi1-a-bSibN (where an average value of a, aavg, and an average value of b, bavg, satisfy the relationships 0.35≤aavg≤0.60, and 0.00