Surface-coated cutting tool and method of manufacturing the same
A surface-coated cutting tool includes a base material and a coating covering the base material. The base material includes a rake face and a flank face. The coating includes a TiCN layer. The TiCN layer has a (422) orientation in a region d 1 in the rake face. The TiCN layer has a (311) orientation in a region d 2 in the flank face.
1. A surface-coated cutting tool comprising:
a base material; and
a coating covering the base material, wherein
the base material includes a rake face and a flank face,
the coating includes a TiCN layer,
the TiCN layer has a (422) orientation in a region d 1 in the rake face,
the TiCN layer has a (311) orientation in a region d 2 in the flank face,
when the rake face and the flank face are continuous with each other with a cutting edge face therebetween,
the region d 1 is a region sandwiched between an imaginary line D 1 and a boundary between the rake face and the cutting edge face, the imaginary line D 1 being 500 μm apart from an imaginary ridge line on the rake face, the imaginary ridge line being an intersection between a surface obtained by extending the rake face and a surface obtained by extending the flank face, and
the region d 2 is a region sandwiched between an imaginary line D 2 and a boundary between the flank face and the cutting edge face, the imaginary line D 2 being 500 μm apart from the imaginary ridge line on the flank face, and
when the rake face and the flank face are continuous with each other with a ridge line therebetween,
the region d 1 is a region sandwiched between the ridge line and an imaginary line D 1 which is 500 μm apart from the ridge line on the rake face, and
the region d 2 is a region sandwiched between the ridge line and an imaginary line D 2 which is 500 μm apart from the ridge line on the flank face.
2. The surface-coated cutting tool according to claim 1 , wherein
the TiCN layer having the (311) orientation means that, among texture coefficients TC (hkl) defined by equation (1) below, a texture coefficient TC (311) of a (311) plane in the TiCN layer is greater than a texture coefficient of any other crystal orientation plane, and
the TiCN layer having the (422) orientation means that, among the texture coefficients TC (hkl) defined by equation (1) below, a texture coefficient TC (422) of a (422) plane in the TiCN layer is greater than a texture coefficient of any other crystal orientation plane,
TC
(
hkl
)
=
I
(
hkl
)
I
0
(
hkl
)
{
1
8
∑
x
,
y
,
z
I
(
h
x
k
y
l
z
)
I
0
(
h
x
k
y
l
z
)
}
-
1
(
1
)
where
I(hkl) and I(h x k v l z ) represent a measured diffraction intensity of a (hkl) plane and a measured diffraction intensity of a (h x k v l z ) plane, respectively,
I o (hkl) and I o (h x k v l z ) represent an average value of powder diffraction intensities of TiC and TiN of a (hkl) plane according to a JCPDS database and an average value of powder diffraction intensities of TiC and TiN of a (h x k v l z ) plane according to the JCPDS database, respectively, and
(hkl) and (h x k v l z ) each represent any one of eight planes including a (111) plane, a (200) plane, a (220) plane, a (311) plane, a (331) plane, a (420) plane, a (422) plane, and a (511) plane.
3. The surface-coated cutting tool according to claim 2 , wherein a ratio TC flank (311)/TC flank (422) of a (311) texture coefficient to a (422) texture coefficient in the region d 2 of the flank face is greater than 1.
4. The surface-coated cutting tool according to claim 2 , wherein a ratio TC flank (422)/TC rake (422) of a (422) texture coefficient in the region d 2 of the flank face to a (422) texture coefficient in the region d 1 of the rake face is not greater than 1.
5. The surface-coated cutting tool according to claim 1 , wherein the TiCN layer has a thickness of not less than 6 μm and not greater than 10 μm.
6. The surface-coated cutting tool according to claim 1 , wherein the base material includes one selected from the group consisting of cemented carbide, cermet, high-speed steel, ceramic, cBN sintered body, and diamond sintered body.
7. The surface-coated cutting tool according to claim 6 , wherein when the base material is cemented carbide, the base material contains cobalt in an amount of not less than 7 mass % and not greater than 12 mass % relative to a total mass of the base material.
8. The surface-coated cutting tool according to claim 1 , wherein the coating further includes an Al 2 O 3 layer formed on the TiCN layer.
9. The surface-coated cutting tool according to claim 8 , wherein the Al 2 O 3 layer has a thickness of not less than 0.5 μm and not greater than 4 μm.
10. A method of manufacturing a surface-coated cutting tool according to claim 1 , the method comprising:
a base material preparation step of preparing the base material;
a TiCN layer covering step of covering at least part of the rake face and at least part of the flank face with the TiCN layer; and
a peening step of peening the TiCN layer in the flank face,
wherein the TiCN layer covering step is performed by chemical vapor deposition and includes discontinuously supplying a source gas of the TiCN layer.
11. The method according to claim 10 , wherein
the coating further includes an Al 2 O 3 layer formed on the TiCN layer, and
the method further comprises an Al 2 O 3 layer stacking step of stacking the Al 2 O 3 layer on the TiCN layer after the TiCN layer covering step or the peening step.