Ceramic matrix laminates

Abstract

The invention provides systems and methods for forming low density ceramic felt material cores which are sandwiched between ceramic matrix composites to form a ceramic matrix laminate possessing a high strength-to-density ratio while maintaining a stiffness required for mechanical applications. The core and face plates are coupled together using a chemical vapor process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exemplary exploded perspective view of a core preform.

FIG. 2 is a block diagram of an exemplary lamination method according to the invention.

FIG. 3 is an exemplary exploded perspective view of a laminate compressing assembly.

FIG. 4 is a block diagram of an exemplary compression lamination method according to the invention.

FIG. 5 is a photomicrograph of a CML produced according to the invention wherein the top and bottom face plates are ceramic matrix composites and the middle area is the core. (magnification ˜50×)

FIG. 6 is a block diagram of an exemplary core prefabrication method according to the invention.

FIG. 7 is a photomicrograph of a fractured end of an SiC coated carbon fiber after oxidation according to the invention.

Claims

1. A ceramic matrix laminate comprising: a first and a second face plate, the first face plate having a density and the second face plate having a density;a core material having a density, the core material being disposed between the first and second face plates; andthe core material being coupled to the first and second face plates using a chemical vapor process.

2. The laminate according to claim 1 wherein the core material density is less than the first face plate density and the second face plate density, and wherein the core material density is about 0.2 g/cm3 to about 2.0 g/cm3, the first face plate density is about 1.9 g/cm3 to about 2.5 g/cm3, and the second face plate density is about 1.9 g/cm3 to about 2.5 g/cm3.

3. The laminate according to claim 2 wherein the core material comprises an open cell foam.

4. A ceramic matrix laminate comprising: a first and a second face plate, the first face plate having a density and the second face plate having a density;a prefabricated core material having a density, the core material being disposed between the first and second face plates; andthe core material being coupled to the first and second face plates using a chemical vapor process.

5. The laminate according to claim 4 wherein the prefabricated core material density is in a range of about 0.2 g/cm3 to about 1.0 g/cm3, and the prefabricated core material density is less than the first face plate density and the second face plate density.

6. The laminate according to claim 5 wherein the prefabricated core material comprises graphite fibers coated with SiC.

7. The laminate according to claim 5 wherein the prefabricated core material comprises hollow SiC fibers.

8. A method of fabricating a ceramic matrix laminate comprising: forming a preform comprising: providing a core substrate;providing a face plate precursor;disposing the core substrate on one side of the face plate precursor;coupling the core substrate to the face plate precursor; andinfiltrating the preform.

9. A method of fabricating a ceramic matrix laminate comprising: forming a preform comprising: providing a core substrate;providing a first and a second face plate precursor;disposing the core substrate between the first and second face plate precursors;coupling the core substrate to the first and second face plate precursors; andinfiltrating the preform.

10. The method according to claim 9 wherein infiltrating comprises infiltrating SiC through the preform.

11. The method according to claim 10 further comprising applying a compression assembly about the preform before infiltrating the preform.

12. A method of fabricating a core material comprising: providing a core substrate;applying a compression assembly about the core substrate;infiltrating the compression assembly with the core substrate; andremoving the compression assembly from the core substrate after infiltrating.

13. The method according to claim 12 wherein infiltrating comprises infiltrating SiC through the compression assembly with the core substrate.

14. The method of claim 13 further comprising oxidizing the core substrate after infiltration.

15. A method of fabricating a ceramic matrix laminate comprising: forming a preform comprising: fabricating a core substrate comprising: providing a core substrate;applying a compression assembly about the core substrate;infiltrating the compression assembly with the core substrate; andremoving the compression assembly from the core substrate after infiltrating;providing a first and a second face plate precursor;disposing the fabricated core substrate between the first and second face plate precursors;coupling the core substrate to the first and second face plate precursors; andinfiltrating the preform.

16. The method according to claim 15 wherein infiltrating the compression assembly comprises infiltrating SiC through the compression assembly with the core substrate.

17. The method of claim 16 further comprising oxidizing the core substrate after infiltrating the compression assembly.

18. The method according to claim 15 wherein infiltrating the preform comprises infiltrating SiC through the preform.

19. The method according to claim 18 further comprising applying a compression assembly about the preform before infiltrating the preform.

20. A ceramic matrix laminate comprising: two load-bearing face plates; anda core material sandwiched between the two load-bearing face plates, wherein the core material is less dense than the two load-bearing face plates, and wherein the core material is bonded to the load-bearing face plates via at least one of the following processes:a chemical vapor infiltration process; anda chemical vapor deposition process.

21. The ceramic matrix laminate of claim 20, wherein the core material comprises at least one of: a carbon felt, a SiC felt, and insulation material.

22. The ceramic matrix laminate of claim 20, wherein each load-bearing face plate comprises at least one of: a SiC ceramic matrix composite, a Nicalon fiber mat, and a SiC fiber mat.

23. The ceramic matrix laminate of claim 20, wherein the core material and the load-bearing face plates are joined together prior to being bonded via the chemical vapor infiltration process.

24. The ceramic matrix laminate of claim 23, wherein the core material and the load-bearing face plates are joined together via at least one of: sewing, stapling, gluing, and compressing.

25. The ceramic matrix laminate of claim 20, wherein the core material comprises hollow fibers.

26. The ceramic matrix laminate of claim 20, wherein the core material has a shear stress of at least about 800 psi.