US 12,319,991 B2
Base material and cutting tool
Takato Yamanishi, Osaka (JP); and Keiichi Tsuda, Osaka (JP)
Assigned to SUMITOMO ELECTRIC INDUSTRIES, LTD., Osaka (JP)
Appl. No. 17/776,245
Filed by Sumitomo Electric Industries, Ltd., Osaka (JP)
PCT Filed Apr. 1, 2021, PCT No. PCT/JP2021/014191
§ 371(c)(1), (2) Date May 12, 2022,
PCT Pub. No. WO2021/240995, PCT Pub. Date Dec. 2, 2021.
Claims priority of application No. 2020-091481 (JP), filed on May 26, 2020.
Prior Publication US 2022/0389544 A1, Dec. 8, 2022
Int. Cl. C22C 29/08 (2006.01); B23B 27/14 (2006.01)
CPC C22C 29/08 (2013.01) [B23B 27/148 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A base material made of a cemented carbide,
the cemented carbide including a first hard phase and a binder phase,
the first hard phase consisting of WC particles,
the binder phase including at least one element selected from Co and Ni,
the base material comprising a body portion, and a surface portion provided on a surface of the body portion,
the surface portion having a thickness less than or equal to an average particle size in the first hard phase, and
a ratio of an area proportion of the binder phase in a surface of the surface portion to an area proportion of the binder phase in a cross section of the body portion being not less than 1.2 and not more than 2.0.