Alloy, protective layer and component

Patent metadata

Field	Value
Publication number	US-11092034-B2
Application number	US-201214236785-A
Country	US
Kind code	B2
Filing date	Jun 22, 2012
Priority date	Aug 9, 2011
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

Known protective layers having a high Cr content and additionally a silicon form brittle phases which additionally become brittle under the influence of carbon during use. The protective layer hereof has a composition 22% to 24% cobalt (Co), 10.5% to 11.5% aluminum (AI), 0.2% to 0.4% yttrium (Y) and/or at least one equivalent metal from the group comprising scandium and the rare earth elements, 14% to 16% chrome (Cr), optionally 0.3% to 0.9% tantalum, the remainder nickel (Ni).

First claim

The invention claimed is:

1. A component, of a gas turbine, including
a substrate of the component which is nickel-based or cobalt-based;
a plasma-sprayed protective layer consisting of an alloy, the alloy consists of alloying elements, the alloying elements of the alloy consist of
22% to 24% wt. % cobalt (Co),
14% to 16% wt. % chromium (Cr),
10.5% to 11.5% wt. % aluminum (Al),
0.2% to 0.4% wt. % yttrium (Y),
0.3% to 0.9% wt. % tantalum (Ta),
and balance of the alloy is nickel (Ni),
the protective layer residing over the substrate in order to protect against corrosion and oxidation at high temperatures; and
a ceramic thermal barrier layer applied onto the protective layer,
wherein proportions of the alloying elements of the alloy of the protective layer are selected to avoid forming brittle phases at 950° C. or higher, and to protect the substrate against corrosion and oxidation while the protective layer is exposed to exhaust gases at 950° C. or higher, wherein the brittle phases include alpha phase of Co, alpha phase of Cr, and sigma phase of Cr; and wherein the alloy protects the substrate against corrosion and oxidation at 950° C. or higher, and is ductile enough to be able to accommodate possible deformations of the substrate and not crack to avoid providing points of attack for oxidation and corrosion at 950° C. or higher.

2. The component as claimed in claim 1 , wherein the alloy includes 0.3 wt. % yttrium (Y).

3. The component as claimed in claim 1 , wherein the alloy contains at least 0.4 wt. % tantalum (Ta).

4. The component as claimed in claim 1 , wherein nickel (Ni) forms a matrix of the alloy.

5. The component as claimed in claim 1 , wherein the plasma spraying comprises APS or high velocity spraying (HVOF).

6. The component as claimed in claim 1 , wherein the alloy includes 23 wt. % Co.

7. The component as claimed in claim 1 , wherein the ceramic thermal barrier layer consists of partially or fully stabilized ZrO2.

8. The component as claimed in claim 1 , wherein the protective layer does not include silicon precipitates.

Assignees

• Stamm Werner
• Siemens Energy Global Gmbh & Co Kg

Inventors

• Stamm Werner

Classifications

• C22C19/056

  with the maximum Cr content being at least 10% but less than 20% · CPC title

• C23C4/073

  containing MCrAl or MCrAlY alloys, where M is nickel, cobalt or iron, with or without non-metal elements · CPC title

• C22C19/057

  with the maximum Cr content being less 10% · CPC title

• C23C28/3215

  at least one MCrAlX layer · CPC title

• Y10T428/12611

  Oxide-containing component · CPC title