Coated cutting tool
A coated cutting tool according to the present invention is 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 formed on a surface of the lower layer, and an upper layer formed on a surface of the intermediate layer; the lower layer is a predetermined Ti compound layer with a predetermined average thickness; the intermediate layer is an α-type aluminum oxide layer with a predetermined average thickness; the upper layer is a Ti carbonitride layer with a predetermined average thickness; and a texture coefficient of a predetermined plane of each of the α-type aluminum oxide layer and the Ti carbonitride layer falls within a predetermined range.
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 formed on a surface of the lower layer, and an upper layer formed on a surface of the intermediate layer;
the lower layer is a Ti compound layer of one or more layers selected from the group consisting of a Ti carbide layer, a Ti nitride layer, a Ti carbonitride layer, a Ti carboxide layer and a Ti oxycarbonitride layer;
an average thickness of the lower layer is from 3.0 μm or more to 15.0 μm or less;
the intermediate layer is comprised of an α-type aluminum oxide layer;
an average thickness of the intermediate layer is from 3.0 μm or more to 15.0 μm or less;
in the α-type aluminum oxide layer, a texture coefficient TC (110) of a (110) plane represented by formula (1) below is from 1.5 or more to 6.5 or less;
the upper layer is comprised of a Ti carbonitride layer;
an average thickness of the upper layer is from 1.5 μm or more to 8.0 μm or less; and
in the Ti carbonitride layer in the upper layer, a texture coefficient TC (511) of a (511) plane represented by formula (2) below is from 1.5 or more to 5.0 or less,
TC
(
110
)
=
I
(
110
)
I
0
(
110
)
{
1
8
Σ
I
(
h
k
l
)
I
0
(
h
k
l
)
}
-
1
(
1
)
(In formula (1), I (hkl) denotes a peak intensity for an (hkl) plane in X-ray diffraction of the α-type aluminum oxide layer, I 0 (hkl) denotes a standard diffraction intensity for an (hkl) plane which is indicated on JCPDS Card No. 10-0173 for α-type aluminum oxide, and (hkl) refers to the eight crystal planes of (012), (104), (110), (113), (024), (116), (214) and (030),)
TC
(
511
)
=
I
(
511
)
I
0
(
511
)
{
1
6
Σ
I
(
h
k
l
)
I
0
(
h
k
l
)
}
-
1
(
2
)
(In formula (2), I (hkl) denotes a peak intensity for an (hkl) plane in X-ray diffraction of the Ti carbonitride layer, I 0 (hkl) denotes an average value of a standard diffraction intensity for an (hkl) plane which is indicated on JCPDS Card No. 32-1383 for Ti carbide and a standard diffraction intensity for an (hkl) plane which is indicated on JCPDS Card No. 32-1420 for Ti nitride, and (hkl) refers to the six crystal planes of (111), (200), (220), (311), (422) and (511).
2. The coated cutting tool according to claim 1 , wherein, in the Ti carbonitride layer in the upper layer, the texture coefficient TC (511) is from 3.0 or more to 5.0 or less.
3. The coated cutting tool according to claim 1 , wherein, in the α-type aluminum oxide layer, the texture coefficient TC (110) is from 4.0 or more to 6.5 or less.
4. The coated cutting tool according to claim 1 , wherein an average thickness of the entire coating layer is from 7.5 μm or more to 25.0 μm or less.
5. The coated cutting tool according to claim 1 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
6. The coated cutting tool according to claim 2 , wherein, in the α-type aluminum oxide layer, the texture coefficient TC (110) is from 4.0 or more to 6.5 or less.
7. The coated cutting tool according to claim 2 , wherein an average thickness of the entire coating layer is from 7.5 μm or more to 25.0 μm or less.
8. The coated cutting tool according to claim 3 , wherein an average thickness of the entire coating layer is from 7.5 μm or more to 25.0 μm or less.
9. The coated cutting tool according to claim 6 , wherein an average thickness of the entire coating layer is from 7.5 μm or more to 25.0 μm or less.
10. The coated cutting tool according to claim 2 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
11. The coated cutting tool according to claim 3 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
12. The coated cutting tool according to claim 4 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
13. The coated cutting tool according to claim 6 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
14. The coated cutting tool according to claim 7 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
15. The coated cutting tool according to claim 8 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.
16. The coated cutting tool according to claim 9 , wherein the substrate is a cemented carbide, cermet, ceramic or a cubic boron nitride sintered body.