Boron nitride aerogel interface coating precursor for ceramic matrix composites

Patent metadata

Field	Value
Publication number	US-12157704-B2
Application number	US-202218084932-A
Country	US
Kind code	B2
Filing date	Dec 20, 2022
Priority date	Dec 20, 2022
Publication date	Dec 3, 2024
Grant date	Dec 3, 2024

Abstract

A method of forming a ceramic matrix composite (CMC) comprises applying a boron nitride (BN) aerogel to a fibrous material to form a pretreated fibrous material, depositing, using chemical vapor infiltration (CVI), a BN interface coating (IFC) on the pretreated fibrous material, and depositing a matrix on the BN IFC and the pretreated fibrous material.

First claim

The invention claimed is:

1. A method of forming a ceramic matrix composite (CMC), the method comprising:
applying a boron nitride (BN) aerogel to a fibrous material to form a pretreated fibrous material;
depositing, using chemical vapor infiltration (CVI), a BN interface coating (IFC) on the pretreated fibrous material; and
depositing a matrix on the BN IFC and the pretreated fibrous material.

2. The method of claim 1 , wherein the step of applying the BN aerogel comprises:
immersing the fibrous material in a bath of water and hexagonal BN (h-BN) to form a slurry-coated fibrous material; and
freeze-drying the slurry coated fibrous material.

3. The method of claim 2 , wherein the fibrous material comprises a sheet of ceramic fibers.

4. The method of claim 3 , wherein the step of immersing the fibrous material comprises:
pulling the sheet through the bath of water and h-BN under tension.

5. The method of claim 3 and further comprising:
forming a pre-preg sheet by injecting the sheet with a polymer resin and curing the sheet.

6. The method of claim 5 , wherein the polymer resin comprises one of polyvinyl alcohol and polyvinyl butyral.

7. The method of claim 5 and further comprising:
forming plies from the pre-preg sheet; and
laying up the plies into a preform.

8. The method of claim 7 and further comprising:
prior to depositing the BN IFC, consolidating the BN aerogel by heating the preform to a temperature ranging from 1200° C. to 1500° C.

9. The method of claim 2 , wherein the fibrous ceramic material comprises a preform.

10. The method of claim 9 and further comprising:
prior to depositing the BN IFC, consolidating the BN aerogel by heating the preform to a temperature ranging from 1200° C. to 1500° C.

11. The method of claim 2 , wherein the fibrous material comprises an individual tow.

12. The method of claim 11 , wherein the step of immersing the fibrous material comprises:
pulling the tow through the bath of water and h-BN under tension.

13. The method of claim 12 and further comprising:
sizing the tow; and
weaving the tow into a sheet.

14. The method of claim 13 and further comprising:
forming plies from the sheet; and
laying up the plies into a preform.

15. The method of claim 14 and further comprising:
prior to depositing the BN IFC, consolidating the BN aerogel by heating the preform to a temperature ranging from 1200° C. to 1500° C.

16. The method of claim 2 , wherein the BN aerogel comprises BN nanotubes and BN nanosheets.

17. The method of claim 2 , wherein the BN IFC comprises h-BN.

18. The method of claim 2 , wherein the step of depositing the matrix comprises at least one of chemical vapor infiltration, slurry infiltration, melt infiltration, and polymer infiltration and pyrolysis.

19. The method of claim 2 , wherein the matrix comprises silicon carbide (SiC).

20. The method of claim 2 and further comprising:
prior to the step of depositing the matrix, depositing, using CVI, an oxidation resistant coating on the pretreated fibrous material, the oxidation resistant coating comprising at least one of silicon-doped BN, SiC, and carbon.

Assignees

• Raytheon Tech Corp
• Rtx Corp

Inventors

• Lenz Brendan
• Callaway Evan B

Classifications

• C04B2235/616

  Liquid infiltration of green bodies or pre-forms · CPC title

• C04B2235/614

  Gas infiltration of green bodies or pre-forms · CPC title

• C04B2235/386

  Boron nitrides · CPC title

• C04B2235/3826

  Silicon carbides · CPC title

• C04B41/5059

  Silicon carbide · CPC title