Coated cutting tool
A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, wherein: the coating layer comprises a lower layer, an intermediate layer and an upper layer, the lower layer, the intermediate layer and the upper layer being laminated in order from the substrate side toward a surface side of the coating layer; the lower layer comprises a Ti compound layer; the intermediate layer contains α-Al 2 O 3 ; the upper layer contains TiCN; an average thickness of each of the lower layer, the intermediate layer, and the upper layer is within a specific range; a ratio of a length of Σ3 grain boundaries to a total 100% length of all grain boundaries in a specific region of the upper layer is from 20% or more to 60% or less; and a ratio of (111)-oriented grains in the upper layer is 30 area % or more.
1. A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, wherein:
the coating layer comprises a lower layer, an intermediate layer and an upper layer, the lower layer, the intermediate layer and the upper layer being laminated in order from the substrate side toward a surface side of the coating layer;
the lower layer comprises one Ti compound layer or two or more Ti compound layers containing a Ti compound of Ti and an element of at least one kind selected from the group consisting of C, N, O and B;
the intermediate layer contains α-Al 2 O 3 ;
the upper layer contains TiCN;
an average thickness of the lower layer is from 4.0 μm or more to 10.0 μm or less;
an average thickness of the intermediate layer is from 3.0 μm or more to 10.0 μm or less;
an average thickness of the upper layer is from 1.5 μm or more to 6.5 μm or less;
a ratio of a length of Σ3 grain boundaries to a total 100% length of all grain boundaries in a specific region of the upper layer is from 20% or more to 60% or less; and
a ratio of (111)-oriented grains in the upper layer is 30 area % or more.
2. The coated cutting tool according to claim 1 , wherein the ratio of (111)-oriented grains in the upper layer is 55 area % or less.
3. The coated cutting tool according to claim 1 , wherein a content of chlorine (Cl) in the upper layer is 0.1 atom % or less.
4. The coated cutting tool according to claim 1 , wherein an average thickness of the coating layer is from 10.0 μm or more to 25.0 μm or less.
5. The coated cutting tool according to claim 1 , wherein the Ti compound layer is at least one kind selected from the group consisting of TiN, TiC, TiCN, TiCNO, TiON and TiB 2 .
6. The coated cutting tool according to claim 1 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
7. The coated cutting tool according to claim 2 , wherein a content of chlorine (Cl) in the upper layer is 0.1 atom % or less.
8. The coated cutting tool according to claim 2 , wherein an average thickness of the coating layer is from 10.0 μm or more to 25.0 μm or less.
9. The coated cutting tool according to claim 3 , wherein an average thickness of the coating layer is from 10.0 μm or more to 25.0 μm or less.
10. The coated cutting tool according to claim 7 , wherein an average thickness of the coating layer is from 10.0 μm or more to 25.0 μm or less.
11. The coated cutting tool according to claim 2 , wherein the Ti compound layer is at least one kind selected from the group consisting of TiN, TiC, TiCN, TiCNO, TiON and TiB 2 .
12. The coated cutting tool according to claim 3 , wherein the Ti compound layer is at least one kind selected from the group consisting of TiN, TiC, TiCN, TiCNO, TiON and TiB 2 .
13. The coated cutting tool according to claim 4 , wherein the Ti compound layer is at least one kind selected from the group consisting of TiN, TiC, TiCN, TiCNO, TiON and TiB 2 .
14. The coated cutting tool according to claim 7 , wherein the Ti compound layer is at least one kind selected from the group consisting of TiN, TiC, TiCN, TiCNO, TiON and TiB 2 .
15. The coated cutting tool according to claim 8 , wherein the Ti compound layer is at least one kind selected from the group consisting of TiN, TiC, TiCN, TiCNO, TiON and TiB 2 .
16. The coated cutting tool according to claim 9 , wherein the Ti compound layer is at least one kind selected from the group consisting of TiN, TiC, TiCN, TiCNO, TiON and TiB 2 .
17. The coated cutting tool according to claim 10 , wherein the Ti compound layer is at least one kind selected from the group consisting of TiN, TiC, TiCN, TiCNO, TiON and TiB 2 .
18. The coated cutting tool according to claim 2 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
19. The coated cutting tool according to claim 3 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
20. The coated cutting tool according to claim 4 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.