Ceramic composites with an intermediate layer having a carbon sink material for high temperature applications

Patent metadata

Field	Value
Publication number	US-11655194-B2
Application number	US-201916655626-A
Country	US
Kind code	B2
Filing date	Oct 17, 2019
Priority date	Oct 17, 2019
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

Coated components, along with methods of their formation, are provided. The coated component includes a ceramic substrate having a surface; an intermediate layer on the surface of the ceramic substrate; and an environmental barrier coating on the intermediate layer. The intermediate layer includes a carbon-sink material that inhibits accumulation of free carbon from a carbon-containing species within the intermediate layer, the ceramic substrate, or both.

First claim

What is claimed is:

1. A coated component comprising:
a ceramic substrate having a surface;
an intermediate layer directly on the surface of the ceramic substrate, wherein the intermediate layer comprises 50% to 99%, by weight of silicon carbide and a carbon-sink material dispersed within the silicon carbide, wherein the carbon-sink material inhibits accumulation of free carbon from a carbon-containing species within the intermediate layer, the ceramic substrate, or both; and
an environmental barrier coating on the intermediate layer.

2. The coated component as in claim 1 , wherein the ceramic substrate comprises silicon carbide.

3. The coated component as in claim 1 , wherein the ceramic substrate comprises a silicon carbide matrix and silicon carbide fiber.

4. The coated component as in claim 1 , wherein the carbon-sink material comprises one or more carbides that react to form another carbide with a lower ratio of a carbiding element to carbon upon exposure to free carbon at a reaction temperature.

5. The coated component as in claim 4 , wherein the one or more carbides comprise ditungsten carbide, dimolybdenum carbide, diniobium carbide, ditantalum carbide, or a mixture thereof such that, upon reaction with carbon, react to form, respectively, tungsten carbide, molybdenum carbide, niobium carbide, tantalum carbide, or a mixture thereof.

6. The coated component as in claim 1 , wherein the carbon-sink material comprises a carbide that has a non-stoichiometry allowing the carbide to convert to a second carbide upon exposure to carbon.

7. The coated component as in claim 6 , wherein the carbide of the carbon-sink material comprises TiC a having a Ti:C ratio that is greater than 1:1 to 2:1.

8. The coated component as in claim 1 , wherein the carbon-sink material comprises a carbon getter.

9. The coated component as in claim 8 , wherein the intermediate layer comprises the carbon getter dispersed within the silicon carbide.

10. The coated component as in claim 8 , wherein the carbon getter comprises a metal.

11. The coated component as in claim 10 , wherein the metal comprises molybdenum, tungsten, niobium, tantalum, titanium, zirconium, hafnium, or a mixture thereof.

12. The coated component as in claim 8 , wherein the carbon getter comprises a silicide.

13. The coated component as in claim 12 , wherein the carbon getter forms a porous intermediate layer.

14. The coated component as in claim 1 , wherein the intermediate layer has a thickness of about 1μm to about 250 μm.

15. A method of coating a ceramic component on its outer surface, wherein the ceramic component comprises silicon carbide, the method comprising:
forming an intermediate layer directly on the outer surface of the ceramic component, wherein the intermediate layer comprises 50% to 99%, by weight of silicon carbide and a carbon-sink material dispersed within the silicon carbide, wherein the carbon-sink material inhibits accumulation of free carbon from a carbon-containing species within the intermediate layer, the ceramic component, or both; and
forming an environmental barrier coating on the intermediate layer.

16. The method of claim 15 , wherein the carbon-sink material comprises a carbide that reacts to form another carbide with a lower ratio of a carbiding element to carbon upon exposure to free carbon at a reaction temperature.

17. The method of claim 15 , wherein the carbon-sink material comprises a carbide that has a non-stoichiometry allowing the carbide to convert to another carbide upon exposure to carbon.

18. The method of claim 15 , wherein the intermediate layer comprises a carbon getter dispersed within the silicon carbide.

19. The method of claim 17 , wherein the carbide of the carbon-sink material comprises TiC a having a Ti:C ratio that is greater than 1:1 to 2:1.

Assignees

• Gen Electric

Inventors

• Luthra Krishan Lal
• Kirby Glen Harold
• Wan Julin
• Rosenzweig Larry Steven

Classifications

• C04B41/5057

  Carbides · CPC title

• C04B41/522

  Multiple coatings, for one of the coatings of which at least one alternative is described · CPC title

• C04B2235/5244

  Silicon carbide · CPC title

• C04B41/5071

  Silicides · CPC title

• C04B2235/3826

  Silicon carbides · CPC title