US 12,325,074 B2
Cutting tool
Yasuki Kido, Itami (JP); Susumu Okuno, Itami (JP); and Masahito Hikiji, Itami (JP)
Assigned to SUMITOMO ELECTRIC HARDMETAL CORP., Itami (JP)
Appl. No. 17/776,608
Filed by Sumitomo Electric Hardmetal Corp., Itami (JP)
PCT Filed Jun. 11, 2020, PCT No. PCT/JP2020/022994
§ 371(c)(1), (2) Date May 13, 2022,
PCT Pub. No. WO2021/250841, PCT Pub. Date Dec. 16, 2021.
Prior Publication US 2022/0402043 A1, Dec. 22, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. B23B 27/14 (2006.01)
CPC B23B 27/148 (2013.01) [B23B 2224/04 (2013.01); B23B 2228/105 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A cutting tool comprising:
a substrate; and
a coating film disposed on the substrate, wherein
the coating film includes an α-Al2O3 layer,
the α-Al2O3 layer includes a plurality of α-Al2O3 crystal grains, and has a TC(006) of more than 5 in texture coefficient TC(hkl), and
a hardness H1 of the α-Al2O3 layer at a room temperature and a hardness H2 of the α-Al2O3 layer at 800° C. represent a relation of the following expression A-1:
0<{(H1−H2)/H1}×100<60   Expression A-1.