US 11,717,978 B2
Cemented carbide and cutting tool including same as substrate
Kensei Hamaki, Osaka (JP); Takato Yamanishi, Osaka (JP); and Keiichi Tsuda, Osaka (JP)
Assigned to Sumitomo Electric Industries, Ltd., Osaka (JP)
Appl. No. 17/414,023
Filed by SUMITOMO ELECTRIC INDUSTRIES, LTD., Osaka (JP)
PCT Filed Aug. 11, 2020, PCT No. PCT/JP2020/030541
§ 371(c)(1), (2) Date Jun. 15, 2021,
PCT Pub. No. WO2021/106276, PCT Pub. Date Jun. 3, 2021.
Claims priority of application No. 2019-213275 (JP), filed on Nov. 26, 2019.
Prior Publication US 2022/0048213 A1, Feb. 17, 2022
Int. Cl. C22C 29/08 (2006.01); B26D 1/00 (2006.01); C22C 1/051 (2023.01); C22C 19/03 (2006.01); C22C 19/07 (2006.01); C22C 29/06 (2006.01)
CPC B26D 1/0006 (2013.01) [C22C 1/051 (2013.01); C22C 19/03 (2013.01); C22C 19/07 (2013.01); C22C 29/067 (2013.01); C22C 29/08 (2013.01); B26D 2001/002 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A cemented carbide comprising a first hard phase and a binder phase, wherein
a content ratio of the binder phase is more than or equal to 4 wt % and less than or equal to 15 wt % with respect to the cemented carbide,
the first hard phase is composed of tungsten carbide grains,
the binder phase includes cobalt and nickel as constituent elements,
the binder phase further includes more than or equal to 5 at % and less than or equal to 20 at % of aluminum or chromium as a constituent element,
a ratio Ni/Co of an atomic concentration of the nickel and an atomic concentration of the cobalt in the binder phase is more than or equal to 0.3 and less than 3,
an arbitrary surface or arbitrary cross section of the cemented carbide has
a region R1 interposed between an interface between the tungsten carbide grains and the binder phase and an imaginary line A indicating a location separated by 5 nm from the interface to the binder phase side,
a region R2 interposed between the imaginary line A and an imaginary line B indicating a location separated by 20 nm from the interface to the binder phase side, and
a region R3 other than the region R1 and the region R2 in the binder phase, and
a ratio C5/C20 of a maximum atomic concentration C5 at % of the cobalt in the region R1 and a maximum atomic concentration C20 at % of the cobalt in the region R3 is more than 1, and
the maximum atomic concentration C5 at % and the maximum atomic concentration C20 at % are determined by performing a line analysis in a range including the region R1 and the region R3 adjacent to the region R1 with the region R2 being interposed between the region R3 and the region R1.