US 12,005,507 B2
Cemented carbide and cutting tool including same as substrate
Takato Yamanishi, Osaka (JP); and Keiichi Tsuda, Osaka (JP)
Assigned to Sumitomo Electric Industries, Ltd., Osaka (JP)
Appl. No. 17/294,438
Filed by SUMITOMO ELECTRIC INDUSTRIES, LTD., Osaka (JP)
PCT Filed Jul. 3, 2020, PCT No. PCT/JP2020/026112
§ 371(c)(1), (2) Date May 17, 2021,
PCT Pub. No. WO2021/079561, PCT Pub. Date Apr. 29, 2021.
Claims priority of application No. 2019-194115 (JP), filed on Oct. 25, 2019.
Prior Publication US 2022/0016715 A1, Jan. 20, 2022
Int. Cl. C22C 29/08 (2006.01); B23B 27/14 (2006.01); B23C 5/16 (2006.01)
CPC B23B 27/14 (2013.01) [B23C 5/16 (2013.01); C22C 29/08 (2013.01); B23B 2224/20 (2013.01); B23C 2224/20 (2013.01)] 7 Claims
 
1. A cemented carbide comprising a first hard phase, a second hard phase, and a binder phase, wherein
the first hard phase is composed of tungsten carbide grains,
the second hard phase is composed of carbide grains including niobium or tantalum as a constituent element,
the binder phase includes cobalt, nickel, and chromium as constituent elements,
at least part of the carbide grains of the second hard phase further include tungsten as a constituent element, and
a ratio A/B of A volume % representing a volume ratio of the second hard phase to the cemented carbide to B volume % representing a volume ratio of a total of a niobium element and a tantalum element to the cemented carbide is more than 1.2,
wherein mass ratio of cobalt is 40 mass % or more and 80 mass % or less, mass ratio of chromium is 10 mass % or more and 20 mass % or less, and mass ratio of nickel is 10 mass % or more and 40 mass % or less, each said mass ratio with respect to total mass of the binder phase.