Patent ID: 8187698

Claim:
A cutting tool insert, comprising: a cemented carbide body that comprises 5.0-9.0 wt-% Co, 5.0-11.0 wt-% cubic carbide forming metals selected from group IVb, Vb and VIb of the periodic table and balance WC, and with a weight-ratio of Ta and Nb, when present, between 1.0-3.0 and between Ti and Nb, when present, within 0.5-1.5 and with a coercivity (Hc) of 10.0-15.0 kA/m, whereby the cemented carbide is provided with a 10-30 μm, essentially cubic carbide phase free and binder phase enriched surface zone with average binder phase content in the range 1.2-2.5 times the nominal binder phase content; and a coating that comprises a MTCVD Ti(C,N) as a first layer adjacent the body having a thickness of from 2.5 to 7.0 μm, where the MTCVD-layer comprises an innermost TiN layer adjacent to the body with a Ti(C,N) layer on top, optionally with an additional intermediate TiN layer on top of the Ti(C,N) layer, with a thickness of 0.3-1.0 μm on top of which an α-Al 2 O 3 layer is present, with a thickness of between 2.0 and 5.0 μm and a total thickness of the coating between 5.5 and 9.5 μm, where the texture of the α-Al 2 O 3 layer is TC(006)>2.0 and where the texture coefficients (TC) for the α-Al 2 O 3 layer is determined as follows: TC ⁡ ( hkl ) = I ⁡ ( hkl ) I 0 ⁡ ( hkl ) [ 1 n ⁢ ∑ n = 1 n ⁢ I ⁡ ( hkl ) I 0 ⁡ ( hkl ) ] - 1 where I(hkl)=intensity of the (hkl) reflection, I 0 (hkl)=standard intensity according to JCPDS card no 46-1212, and n=number of reflections used in the calculation, and the (hkl) reflections used are: (012), (104), (110), (006), (113), (202), (024) and (116), where TC(012), TC(110), TC(113), TC(202), TC(024) and TC(116) are all simultaneously <1 and TC(104) is the second highest texture coefficient with TC(104) between 0.5 and 2.0.