Cutting tool

Patent metadata

Field	Value
Publication number	US-12270102-B2
Application number	US-202117924366-A
Country	US
Kind code	B2
Filing date	May 21, 2021
Priority date	May 21, 2021
Publication date	Apr 8, 2025
Grant date	Apr 8, 2025

Abstract

A cutting tool comprises a substrate and a coating provided on the substrate, the coating including a first alumina layer provided on the substrate, a titanium compound layer provided directly on the first alumina layer, and a second alumina layer provided directly on the titanium compound layer, in which a portion adjacent to the titanium compound layer in the first alumina layer serves as an interface region, a portion that is not the interface region in the first alumina layer serves as a non-interface region, a content of nitrogen in the interface region is 0.2 at % or more and 11 at % or less, and a content of nitrogen in the non-interface region is 0 at % or more and 0.15 at % or less; and the titanium compound layer comprises a layer of titanium carbonitroxide adjacent to the first alumina layer.

First claim

The invention claimed is:

1. A cutting tool comprising a substrate and a coating provided on the substrate,
the coating comprising:
a first alumina layer provided on the substrate,
a titanium compound layer provided directly on the first alumina layer, and
a second alumina layer provided directly on the titanium compound layer,

wherein a portion adjacent to the titanium compound layer in the first alumina layer serves as an interface region,
a portion that is not the interface region in the first alumina layer serves as a non-interface region,
a content of nitrogen in the interface region is 0.2 at % or more and 11 at % or less, and
a content of nitrogen in the non-interface region is 0 at % or more and 0.15 at % or less; and
the titanium compound layer comprises a layer of titanium carbonitroxide adjacent to the first alumina layer.

2. The cutting tool according to claim 1 , wherein the first alumina layer has a thickness greater than the thickness of the second alumina layer.

3. The cutting tool according to claim 1 , wherein the titanium compound layer has a thickness of 1 μm or more and 11.5 μm or less.

4. The cutting tool according to claim 1 , wherein the second alumina layer has a thickness of 0.2 μm or more and 6.5 μm or less.

5. The cutting tool according to claim 1 , wherein the first alumina layer has a thickness of 2 μm or more and 21 μm or less.

6. The cutting tool according to claim 5 , wherein the interface region of the first alumina layer is a region sandwiched between an interface S with the titanium compound layer and a virtual plane A parallel to the interface S that passes through a point 0.5 μm away from the interface S in a thickness direction.

7. The cutting tool according to claim 1 , wherein the content of nitrogen in the interface region of the first alumina layer is 0.5 at % or more and 10 at % or less.

8. The cutting tool according to claim 1 , wherein the second alumina layer has a thickness of 0.2 μm or more and 6.5 μm or less, and the titanium compound layer has a residual stress of −3 GPa or more and 0 GPa or less.

9. The cutting tool according to claim 1 , wherein the titanium compound layer further comprises a layer of titanium nitride or titanium carbide.

10. The cutting tool according to claim 1 , wherein the content of nitrogen in the interface region and the content of nitrogen in the non-interface region are atomic ratios to the total of aluminum, oxygen, and nitrogen in the first alumina layer.

11. The cutting tool according to claim 1 , wherein the titanium compound layer has a thickness of 2.5 μm or more and 8.5 μm or less.

12. The cutting tool according to claim 1 , wherein the layer of titanium carbonitroxide has a thickness of 1 μm or more and 8.0 μm or less.

13. The cutting tool according to claim 1 , wherein the coating has a thickness of 10 μm or more and 40 μm or less.

14. The cutting tool according to claim 1 , wherein the coating further includes an underlying layer provided between the substrate and the first alumina layer.

15. The cutting tool according to claim 1 , wherein the coating further includes a surface layer provided on the second alumina layer.

Assignees

• Sumitomo Electric Hardmetal Corp

Inventors

• Okuno Susumu
• Yamanishi Takato
• Hikiji Masahito
• Kobayashi Fumiyoshi

Classifications

• C23C28/044

  coatings specially adapted for cutting tools or wear applications · CPC title

• C23C28/042

  including a refractory ceramic layer, e.g. refractory metal oxides, ZrO2, rare earth oxides · CPC title

• C23C16/34

  Nitrides {(C23C16/303 takes precedence)} · CPC title

• C23C16/32

  Carbides · CPC title

• C23C14/0635

  Carbides · CPC title