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 at least one α-type aluminum oxide layer; and, in the α-type aluminum oxide layer, a texture coefficient TC (0,0,12) of a (0,0,12) plane is from 4.0 or more to 8.4 or less, and a texture coefficient TC (1,1,9) of a (1,1,9) plane is from 0.5 or more to 3.0 or less.
1. A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, wherein:
the coating layer comprises at least one α-type aluminum oxide layer; and
in the α-type aluminum oxide layer, a texture coefficient TC (0,0,12) of a (0,0,12) plane represented by formula (1) below is from 4.0 or more to 8.4 or less, and a texture coefficient TC (1,1,9) of a (1,1,9) plane represented by formula (2) below is from 0.5 or more to 3.0 or less:
T
C
(
0
,
0
,
12
)
=
I
(
0
,
0
,
12
)
I
0
(
0
,
0
,
12
)
{
1
9
∑
I
(
h
,
k
,
l
)
I
o
(
h
,
k
,
l
)
}
-
1
(
1
)
T
C
(
1
,
1
,
9
)
=
I
(
1
,
1
,
9
)
I
0
(
1
,
1
,
9
)
{
1
9
∑
I
(
h
,
k
,
l
)
I
o
(
h
,
k
,
l
)
}
-
1
,
(
2
)
and in formulae (1) and (2), 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 JCPDS Card No. 10-0173 for α-type aluminum oxide, and (h,k,l) refers to the nine crystal planes of (0,1,2), (1,0,4), (1,1,0), (1,1,3), (1,1,6), (2,1,4), (3,0,0), (1,1,9) and (0,0,12).
2. The coated cutting tool according to claim 1 , wherein, in the α-type aluminum oxide layer, the texture coefficient TC (0,0,12) is from 5.0 or more to 8.2 or less.
3. The coated cutting tool according to claim 1 , wherein, in the α-type aluminum oxide layer, the texture coefficient TC (1,1,9) is from 0.7 or more to 2.5 or less.
4. The coated cutting tool according to claim 1 , wherein 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.
5. The coated cutting tool according to claim 1 , wherein an average particle size of the α-type aluminum oxide layer is from 0.1 μm or more to 3.0 μm or less.
6. The coated cutting tool according to claim 1 , wherein an average thickness of the α-type aluminum oxide layer is from 1.0 μm or more to 15.0 μm or less.
7. The coated cutting tool according to claim 1 , wherein the coating layer comprises, between the substrate and the α-type aluminum oxide layer, a Ti compound layer 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.
8. The coated cutting tool according to claim 7 , wherein the Ti compound layer comprises at least one TiCN layer, and an average thickness of the TiCN layer is from 2.0 μm or more to 20.0 μm or less.
9. 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.
10. The coated cutting tool according to claim 1 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
11. The coated cutting tool according to claim 2 , wherein, in the α-type aluminum oxide layer, the texture coefficient TC (1,1,9) is from 0.7 or more to 2.5 or less.
12. The coated cutting tool according to claim 2 , wherein 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.
13. The coated cutting tool according to claim 3 , wherein 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.
14. The coated cutting tool according to claim 2 , wherein an average particle size of the α-type aluminum oxide layer is from 0.1 μm or more to 3.0 μm or less.
15. The coated cutting tool according to claim 3 , wherein an average particle size of the α-type aluminum oxide layer is from 0.1 μm or more to 3.0 μm or less.
16. The coated cutting tool according to claim 4 , wherein an average particle size of the α-type aluminum oxide layer is from 0.1 μm or more to 3.0 μm or less.
17. The coated cutting tool according to claim 2 , wherein an average thickness of the α-type aluminum oxide layer is from 1.0 μm or more to 15.0 μm or less.
18. The coated cutting tool according to claim 3 , wherein an average thickness of the α-type aluminum oxide layer is from 1.0 μm or more to 15.0 μm or less.
19. The coated cutting tool according to claim 2 , wherein the coating layer comprises, between the substrate and the α-type aluminum oxide layer, a Ti compound layer 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.
20. The coated cutting tool according to claim 19 , wherein the Ti compound layer comprises at least one TiCN layer, and an average thickness of the TiCN layer is from 2.0 μm or more to 20.0 μm or less.