US 12,227,836 B2
Cutting tool
Susumu Okuno, Itami (JP); Yasuki Kido, Itami (JP); Fumiyoshi Kobayashi, Itami (JP); and Anongsack Paseuth, Itami (JP)
Assigned to SUMITOMO ELECTRIC HARDMETAL CORP., Itami (JP)
Appl. No. 17/616,679
Filed by Sumitomo Electric Hardmetal Corp., Itami (JP)
PCT Filed Apr. 10, 2020, PCT No. PCT/JP2020/016106
§ 371(c)(1), (2) Date Dec. 6, 2021,
PCT Pub. No. WO2021/205645, PCT Pub. Date Oct. 14, 2021.
Prior Publication US 2022/0331880 A1, Oct. 20, 2022
Int. Cl. C23C 28/04 (2006.01); C23C 16/36 (2006.01); C23C 16/40 (2006.01)
CPC C23C 16/403 (2013.01) [C23C 16/36 (2013.01); C23C 28/044 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A cutting tool comprising a base material and a coating layer provided on the base material,
the coating layer including a titanium carbonitride layer provided on the base material, an intermediate layer provided on the titanium carbonitride layer in contact therewith, and an alumina layer provided on the intermediate layer in contact therewith,
the intermediate layer being composed of a compound made of titanium, carbon, oxygen, and nitrogen,
the intermediate layer having a thickness of more than 1 μm,
when PC1 atomic % represents an atomic ratio of the carbon in an interface between the intermediate layer and the alumina layer, and PC2 atomic % represents an atomic ratio of the carbon at a point A away from the interface by 1 μm on a side of the intermediate layer, a ratio PC1/PC2 of the PC1 to the PC2 being more than or equal to 1.03 and less than or equal to 1.1.