	US 11,814,293 B2
	Diamond polycrystal, tool including diamond polycrystal, and method of producing diamond polycrystal
Hitoshi Sumiya, Osaka (JP); and Katsuko Yamamoto, Osaka (JP)
Assigned to Sumitomo Electric Industries, Ltd., Osaka (JP)
Appl. No. 16/489,641
Filed by Sumitomo Electric Industries, Ltd., Osaka (JP)
PCT Filed Oct. 1, 2018, PCT No. PCT/JP2018/036706 § 371(c)(1), (2) Date Aug. 28, 2019, PCT Pub. No. WO2020/070776, PCT Pub. Date Apr. 9, 2020.
Prior Publication US 2021/0032112 A1, Feb. 4, 2021
Int. Cl. C01B 32/25 (2017.01); C01B 32/26 (2017.01); B23B 27/20 (2006.01)

CPC C01B 32/26 (2017.08) [B23B 27/20 (2013.01); C01B 32/25 (2017.08); C01P 2002/60 (2013.01); C01P 2002/76 (2013.01); C01P 2006/90 (2013.01)]

5 Claims

1. A diamond polycrystal comprising diamond grains,

the diamond polycrystal including a cubic diamond and a 6H type hexagonal diamond, wherein

the cubic diamond and the 6H type hexagonal diamond exist in the same or different diamond grains, and

a ratio Ab₁/Ab₂is more than or equal to 0.4 and less than or equal to 1, Ab₁representing a maximum value of absorption in a range of more than or equal to 1200 cm⁻¹and less than or equal to 1300 cm⁻¹in an infrared absorption spectrum, Ab₂representing a maximum value of absorption in a range of more than or equal to 1900 cm⁻¹and less than or equal to 2100 cm⁻¹.