Coated cutting tool and method of making the same

Patent metadata

Field	Value
Publication number	US-9447491-B2
Application number	US-201314378371-A
Country	US
Kind code	B2
Filing date	Feb 14, 2013
Priority date	Feb 14, 2012
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

The present invention relates to a coated cutting tool with a coating comprising a multilayer structure consisting of alternating layers A and B forming the sequence A/B/A/B/A . . . or alternating layers A and B and an intermediate layer C between the alternating layers A and B forming the sequence A/C/B/C/A/C/B . . . . Layer A consists of ZrAlN and layer B consists of TiN. Layer C comprises one or more metal elements from each of layers A and B and is of different composition and structure than layers A and B. A method for forming the coated cutting tool is also provided. The method comprises heat treatment of the coated cutting tool prior to use.

First claim

The invention claimed is:

1. A coated cutting tool comprising a substrate and a coating on the substrate, wherein said coating comprises a multilayer structure, whereby said multilayer structure comprises:
alternating layers A and B forming the sequence A/B/A/B/A . . . with an individual layer thickness of layer A and layer B of 1-30 nm, whereby layer A consists of Zr1−xAlxN, where 0<x<1, and layer B consists of TiN; and
in an area being used in a cutting operation the multilayer structure consists of alternating layers A and B and an intermediate layer C between said alternating layers A and B forming the sequence A/C/B/C/A/C/B . . . with an individual layer thickness of layer A and layer B of 1-30 nm, whereby layer A consists of Zr1−xAlxN, where 0<x<1, and layer B consists of TiN and whereby layer C comprises one or more metal elements from each of layers A and B and is of different composition and structure than layers A and B.

2. The coated cutting tool of claim 1 , wherein x is from 0.02 up to 0.35.

3. The coated cutting tool of claim 2 , wherein x is from 0.10 up to 0.35.

4. The coated cutting tool of claim 1 , wherein the Zr1−xAlxN is cubic.

5. The coated cutting tool of claim 1 , wherein x is from 0.35 up to 0.90.

6. The coated cutting tool of claim 5 , wherein x is from 0.70 up to 0.90.

7. The coated cutting tool of claim 5 , wherein layer A comprises a hexagonal phase of Zr1−xAlxN.

8. The coated cutting tool of claim 1 , wherein the Zr1−xAlxN is nanocrystalline with an average grain width of less than 10 nm.

9. The coated cutting tool of claim 1 , wherein the individual layer thickness of layer A and layer B is larger than 5 nm and smaller than 20 nm.

10. The coated cutting tool of claim 1 , wherein the multilayer structure has a thickness of 1-20 μm.

11. The coated cutting tool of claim 1 , wherein the coating is a PVD coating.

12. The coated cutting tool of claim 1 , wherein the intermediate layer C has a thickness being between 50 and 150% of the individual layer thickness of layer B.

13. The coated cutting tool of claim 1 , wherein the thickness of the intermediate layer C is at least 3 nm.

14. The coated cutting tool of claim 1 , wherein the intermediate layer C consists of Ti1−yZryN, where y>0.

15. The coated cutting tool of claim 14 , wherein 0<y<1.

16. Method of manufacturing a coated cutting tool comprising a substrate and a coating on the surface of the substrate, the method comprising the steps of:
depositing a multilayer structure consisting of alternating layers A and B forming the sequence A/B/A/B/A . . . with an individual layer thickness of layer A and layer B of 1-30 nm forming at least part of the coating, layer A consisting of Zr1−xAlxN, where 0<x<1, and layer B consisting of TiN; and
heat treating the coating in an area being used in a cutting operation to form an intermediate layer C between said alternating layers A and B so as to form the sequence A/C/B/C/A/C/B . . . , layer C comprising one or more metal elements from each of said alternating layers A and B.

17. The method of claim 16 , wherein the coating is heat treated at at least 1100° C. to form the intermediate layer C.

18. A coated cutting tool comprising a substrate and a coating on the substrate, wherein said coating comprises a multilayer structure, whereby said multilayer structure comprises:
alternating layers A and B; and
in an area being used in a cutting operation the multilayer structure consists of alternating layers A and B and an intermediate layer C between said alternating layers A and B forming the sequence A/C/B/C/A/C/B . . . with an individual layer thickness of layer A and layer B of 1-30 nm, whereby layer A consists of Zr1−xAlxN, where 0<x<1, and layer B consists of TiN and whereby layer C comprises one or more metal elements from each of layers A and B and is of different composition and structure than layers A and B.

19. The coated cutting tool of claim 18 , wherein x is from 0.02 up to 0.35.

20. The coated cutting tool of claim 19 , wherein x is from 0.10 up to 0.35.

21. The coated cutting tool of claim 18 , wherein the Zr1−xAlxN is cubic.

22. The coated cutting tool of claim 18 , wherein x is from 0.35 up to 0.90.

23. The coated cutting tool of claim 22 , wherein x is from 0.70 up to 0.90.

24. The coated cutting tool of claim 18 , wherein layer A comprises a hexagonal phase of Zr1−xAlxN.

25. The coated cutting tool of claim 18 , wherein the Zr1−xAlxN is nanocrystalline with an average grain width of less than 10 nm.

26. The coated cutting tool of claim 18 , wherein the individual layer thickness of layer A and layer B is larger than 5 nm and smaller than 20 nm.

27. The coated cutting tool of claim 18 , wherein the multilayer structure has a thickness of 1-20 μm.

28. The coated cutting tool of claim 18 , wherein the coating is a PVD coating.

29. The coated cutting tool of claim 18 , wherein the intermediate layer C has a thickness being between 50 and 150% of the individual layer thickness of layer B.

30. The coated cutting tool of claim 18 , wherein the thickness of the intermediate layer C is at least 3 nm.

31. The coated cutting tool of claim 18 , wherein the intermediate layer C consists of Ti1−yZryN, where y>0.

32. The coated cutting tool of claim 31 , wherein 0<y<1.

33. The coated cutting tool of claim 27 , wherein the multilayer structure has a thickness of 1-15 μm.

34. The coated cutting tool of claim 10 , wherein the multilayer structure has a thickness of 1-15 μm.

Assignees

• Sandvik Intellectual Property

Inventors

• Ahlgren Mats
• Ghafoor Naureen
• Oden Magnus
• Rogstrom Lina
• Johansson Joesaar Mats

Classifications

• C23C28/044

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

• C23C28/42

  characterized by the composition of the alternating layers · CPC title

• C23C28/042

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

• C23C14/0641 Primary

  Nitrides (C23C14/0617 takes precedence) · CPC title

• B23C2228/10

  Coating · CPC title