Coated cutting tool
A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, the coating layer including at least one α-type aluminum oxide layer, wherein, in the α-type aluminum oxide layer, a texture coefficient TC (1,2,11) of a (1,2,11) plane is 1.4 or more. TC ( 1 , 2 , 11 ) = I ( 1 , 2 , 11 ) I 0 ( 1 , 2 , 11 ) { 1 8 ∑ I ( h , k , l ) I 0 ( h , k , l ) } - 1 ( 1 ) (In formula (1), I (h,k,l) denotes a peak intensity for an (h,k,l) plane in X-ray diffraction of the α-type aluminum oxide layer, I 0 (h,k,l) denotes a standard diffraction intensity for an (h,k,l) plane which is indicated on a JCPDS Card No. 10-0173 for α-type aluminum oxide, and (h,k,l) refers to eight crystal planes of (0,1,2), (1,0,4), (1,1,0), (1,1,3), (0,2,4), (1,1,6), (2,1,4) and (1,2,11).)
1. A coated cutting tool comprising:
a substrate and a coating layer formed on a surface of the substrate, the coating layer including in this order from the substrate side:
a TiCN layer;
an intermediate layer comprised of a compound of at least one kind selected from the group consisting of a Ti carbonate, a Ti oxynitride and a Ti carboxynitride; and
at least one α-type aluminum oxide layer, wherein,
in the α-type aluminum oxide layer, a texture coefficient TC (1,2,11) of a (1,2,11) plane represented by formula (1) below is 1.4 or more,
an average thickness of the α-type aluminum oxide layer is from 1.0 μm or more to 15.0 μm or less, and
a residual stress value in a (1,1,6) plane of the α-type aluminum oxide layer is, in at least part thereof, from −300 MPa or higher to 300 MPa or lower,
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(In formula (1), I (h,k,l) denotes a peak intensity for an (h,k,l) plane in X-ray diffraction of the α-type aluminum oxide layer, I 0 (h,k,l) denotes a standard diffraction intensity for an (h,k,l) plane which is indicated on a JCPDS Card No. 10-0173 for α-type aluminum oxide, and (h,k,l) refers to eight crystal planes of (0,1,2), (1,0,4), (1,1,0), (1,1,3), (0,2,4), (1,1,6), (2,1,4) and (1,2,11).
2. The coated cutting tool according to claim 1 , wherein, in the α-type aluminum oxide layer, the texture coefficient TC (1,2,11) is from 2.0 or more to 6.9 or less.
3. The coated cutting tool according to claim 1 , wherein a ratio I 311 /I 220 of a peak intensity I 311 for a (3,1,1) plane in X-ray diffraction of the TiCN layer to a peak intensity I 220 for a (2,2,0) plane in X-ray diffraction of the TiCN layer is from 1.5 or more to 20.0 or less.
4. The coated cutting tool according to claim 3 , wherein an average thickness of the TiCN layer is from 2.0 μm or more to 20.0 μm or less.
5. The coated cutting tool according to claim 1 , wherein an average thickness of the coating layer is from 3.0 μm or more to 30.0 μm or less.
6. The coated cutting tool according to claim 1 , wherein the coating layer comprises a TiN layer as an outermost layer on a side opposite to the substrate.
7. The coated cutting tool according to claim 1 , wherein the substrate is comprised of any of a cemented carbide, cermet, ceramics and a sintered body containing cubic boron nitride.
8. The coated cutting tool according to claim 2 , wherein a ratio I 311 /I 220 of a peak intensity I 311 for a (3,1,1) plane in X-ray diffraction of the TiCN layer to a peak intensity I 220 for a (2,2,0) plane in X-ray diffraction of the TiCN layer is from 1.5 or more to 20.0 or less.
9. The coated cutting tool according to claim 2 , wherein an average thickness of the coating layer is from 3.0 μm or more to 30.0 μm or less.