Layer system having a two-ply metal layer

Patent metadata

Field	Value
Publication number	US-9435222-B2
Application number	US-201114131572-A
Country	US
Kind code	B2
Filing date	Jul 8, 2011
Priority date	Jul 8, 2011
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

Known protective layers having high Cr content and additional silicon form brittle phases, which additionally become brittle under the effect of carbon during use. The protective layer according to the invention comprises a two-part metal layer, which contains tantalum on the outside.

First claim

The invention claimed is:

1. A layer system at least comprising:
a substrate,
an at least two-layered metallic layer comprised of at least a first bottom layer on the substrate and a second top layer on the bottom layer,
wherein the first bottom layer comprises:
a first alloy comprising at least MCrAl, the first alloy optionally including X 1 , M being at least one of the elements selected from the group consisting of iron, cobalt, and nickel, the first alloy being without tantalum (Ta) and without silicon (Si) and without iron (Fe), and containing at least the following elements, in amounts in percentages by weight:
24%-26% cobalt (Co),
12%-14% chromium (Cr),
5%-15% aluminum (Al),
and a remainder of nickel, and
wherein the second top layer comprises a second alloy comprising at least MCrAl, the second alloy optionally including X 2 , M being at least one of the elements selected from the group consisting of iron, cobalt, and nickel, the alloy including at least one of tantalum (Ta) and iron (Fe), where X 1 , in the first alloy of the first bottom layer, and X 2 , in the second alloy of the second top layer, are independently at least one element selected from the group of elements consisting of: scandium (Sc), rhenium (Re), yttrium (Y), and any of the rare earth group elements other than yttrium (Y), the first alloy including 0.2%45% by weight in total of the at least one element selected from the group of elements, when X 1 is included in the first alloy.

2. The layer system as claimed in claim 1 , in which the first alloy of the first bottom layer comprises cobalt (Co), chromium (Cr), aluminum (Al), yttrium (Y) and nickel (Ni).

3. The layer system as claimed in claim 1 , in which the content of tantalum (Ta) in the second alloy of the second top layer is between 0.1% by weight and 7.0% by weight.

4. The layer system as claimed in claim 1 , in which the content of cobalt (Co) in the second alloy of the second top layer is at least 1% by weight.

5. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises at least 1% by weight chromium (Cr).

6. The layer system as claimed in claim 1 , in which the first alloy of the first bottom layer comprises no rhenium (Re).

7. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises no rhenium (Re).

8. The layer system as claimed in claim 1 , in which at least one of: (1) the first alloy of the first bottom layer and (2) the second alloy of the second top layer contains no silicon (Si).

9. The layer system as claimed in claim 1 , in which the second alloy of the second top layer is nickel-based.

10. The layer system as claimed in claim 1 , in which the first alloy of the first bottom layer is nickel-based.

11. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises at least 1% by weight aluminum (Al).

12. The layer system as claimed in claim 11 , in which the content of aluminum (Al) in the second alloy of the second top layer is between 8% by weight and 12% by weight.

13. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises at least 0.1% by weight of yttrium (Y).

14. The layer system as claimed in claim 1 , in which the content of cobalt (Co) in the second alloy of the second top layer is between 15% by weight and 30% by weight.

15. The layer system as claimed in claim 1 , in which the content of chromium (Cr) in the second alloy of the second top layer is between 12% by weight and 22% by weight.

16. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises nickel (Ni), cobalt (Co), aluminum (Al), chromium (Cr), tantalum (Ta) and optionally yttrium (Y).

17. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises nickel (Ni), cobalt (Co), aluminum (Al), chromium (Cr), tantalum (Ta) and yttrium (Y).

18. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises nickel (Ni), cobalt (Co), aluminum (Al), chromium (Cr), tantalum (Ta), iron (Fe) and optionally yttrium (Y).

19. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises nickel (Ni), cobalt (Co), aluminum (Al), chromium (Cr), tantalum (Ta), iron (Fe) and yttrium (Y).

20. The layer system as claimed in claim 1 , wherein the first alloy of the first bottom layer and the second alloy of the second top layer comprises no iron (Fe).

21. The layer system as claimed in claim 1 , in which the proportion of iron (Fe) in the second alloy of the second top layer is between 0.5% by weight and 5.0% by weight.

22. The layer system as claimed in claim 1 , in which the proportion of aluminum (Al) in the second alloy of the second top layer is between 7% by weight and 8% by weight.

23. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises between 0.1% by weight and 2% by weight of rhenium (Re).

24. The layer system as claimed in claim 1 , in which the content of tantalum (Ta) in the second alloy of the second top layer is between 5% by weight and 6.8% by weight.

25. The layer system as claimed in claim 1 , in which the content of cobalt (Co) in the second alloy of the second top layer is between 11.0% by weight and 14.5% by weight.

26. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises between 0.1% by weight and 0.7% by weight of yttrium (Y).

27. The layer system as claimed in claim 1 , in which the second alloy of the second top layer is between 4% by weight and 7.5% by weight of tantalum (Ta).

28. The layer system as claimed in claim 1 , in which the content of chromium (Cr) in the second alloy of the second top layer is between 18% by weight and 22% by weight.

29. The layer system as claimed in claim 1 , in which the second alloy of the second top layer comprises no yttrium (Y).

30. The layer system as claimed in claim 1 , which is a component of a gas turbine, in which a substrate of the layer system is nickel-based or cobalt-based, and in which a ceramic thermal barrier coating is applied to the second top layer.

Assignees

• Bostanjoglo Georg
• Kaiser Axel
• Stamm Werner
• Steinbach Jan
• Thomaidis Dimitrios
• Siemens Ag

Inventors

• Bostanjoglo Georg
• Kaiser Axel
• Stamm Werner
• Steinbach Jan
• Thomaidis Dimitrios

Classifications

• C23C28/023 Primary

  only coatings of metal elements only · CPC title

• F05D2300/518

  Ductility · CPC title

• Y10T428/12618

  Plural oxides · CPC title

• C23C28/3215

  at least one MCrAlX layer · CPC title

• F05D2300/132

  Chromium · CPC title