	US 12,109,625 B2
	Surface-coated TiN-based cermet cutting tool in which hard coating layer exhibits excellent chipping resistance
Makoto Igarashi, Naka (JP); and Kazutaka Fujiwara, Naka (JP)
Assigned to MITSUBISHI MATERIALS CORPORATION, Tokyo (JP)
Appl. No. 17/279,311
Filed by MITSUBISHI MATERIALS CORPORATION, Tokyo (JP)
PCT Filed Sep. 25, 2019, PCT No. PCT/JP2019/037547 § 371(c)(1), (2) Date Mar. 24, 2021, PCT Pub. No. WO2020/067138, PCT Pub. Date Apr. 2, 2020.
Claims priority of application No. 2018-185620 (JP), filed on Sep. 28, 2018.
Prior Publication US 2022/0055118 A1, Feb. 24, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. B23B 27/14 (2006.01); C22C 1/051 (2023.01); C22C 29/16 (2006.01); C23C 16/34 (2006.01)

CPC B23B 27/148 (2013.01) [C22C 1/051 (2013.01); C22C 29/16 (2013.01); C23C 16/34 (2013.01); B23B 2228/105 (2013.01)]

2 Claims

1. A surface-coated TiN-based cermet cutting tool, comprising:

a body; and

a hard coating layer formed on a surface of the body,

wherein a TiN-based cermet containing a TiN phase as a hard phase component is used as the body,

wherein the hard coating layer includes at least one layer of a titanium carbonitride layer and an aluminum oxide layer,

wherein the body has a linear expansion coefficient of 9.0×10⁻⁶(/K) or more and a thermal conductivity of 30 (W/m·K) or more,

each of the titanium carbonitride layer and the aluminum oxide layer constituting the hard coating layer has a residual compressive stress of 600 to 2,000 MPa,

wherein the TiN-based cermet consists of 70 to 94 area % of the TiN phase, 1 to 25 area % of a Mo₂C phase, and a remainder of a binder phase,

a component of the binder phase consists of Fe and Ni,

a total area ratio of Fe and Ni is 5 to 15 area %, and

an amount of Ni with respect to a total amount of Fe and Ni is 15 to 35 mass %.