Composite structure having ceramic truss core and method for making the same

Patent metadata

Field	Value
Publication number	US-9782951-B2
Application number	US-77943907-A
Country	US
Kind code	B2
Filing date	Jul 18, 2007
Priority date	Jul 18, 2007
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A CMC sandwich used to fabricate CMC structures includes facesheets bonded to a core reinforced with a ceramic truss comprising an array of CMC pins. The binder matrix in the ends of the pins is removed, leaving exposed, flexible ceramic fibers. The exposed ceramic fibers are bent so as to extend parallel to the facesheets, and are bonded to one or more plies of the facesheets. The binder matrix in the ends of the ceramic pins may be removed by mechanical or chemical processes.

First claim

What is claimed is:

1. A method of making a ceramic composite structure, comprising the steps of:
forming a ceramic core, the ceramic core including a ceramic truss comprising a plurality of pins formed from ceramic fibers held in a rigid ceramic binder;
removing the rigid ceramic binder from ends of the pins to expose the ceramic fibers;
bending the ends of the pins;
bonding a facesheet to the ends of the pins; and
protecting a portion of the ceramic core during the removal of the rigid ceramic binder by applying a protective coating to the portion.

2. A method of making a ceramic composite structure, comprising the steps of:
forming a ceramic core, the ceramic core including a ceramic truss comprising a plurality of pins formed from ceramic fibers held in a rigid ceramic binder;
removing the rigid ceramic binder from ends of the pins to expose the ceramic fibers, wherein removing the rigid ceramic binder is performed by etching the ends of the pins;
bending the ends of the pins; and
bonding a facesheet to the ends of the pins.

3. A method of making a ceramic composite structure, comprising the steps of:
forming a ceramic core using ceramic fibers, the ceramic core including a ceramic truss comprising a plurality of pins formed from ceramic fibers held in a rigid ceramic binder;
removing the rigid ceramic binder from ends of the pins to expose the ceramic fibers, wherein removing the rigid ceramic binder is performed by pulverizing the ends of the pins;
bending the ends of the pins; and
bonding a facesheet to the ends of the pins.

4. A method of making a ceramic truss core used in a ceramic composite structure, the ceramic truss core including ceramic fibers, the method comprising the steps of:
forming a ceramic truss using a plurality of ceramic composite pins, wherein the plurality of ceramic composite pins comprise ceramic fibers held in a matrix comprising a rigid ceramic, wherein forming includes:
inserting pin stock into a carrier material, and
cutting the plurality of ceramic composite pins stock to a length such that ends of the plurality of ceramic composite pins extend beyond the carrier material;

removing the matrix from ends of the plurality of ceramic composite pins to expose the ceramic fibers; and
applying a coating on the carrier material that protects the carrier material during removal of the matrix.

5. A method of making a ceramic truss core used in a ceramic composite structure, the ceramic truss core including ceramic fibers, the method comprising the steps of:
forming a ceramic truss using a plurality of ceramic composite pins, wherein the plurality of ceramic composite pins comprise ceramic fibers held in a matrix comprising a rigid ceramic; and,
removing the matrix from ends of the plurality of ceramic composite pins to expose the ceramic fibers, wherein removing is performed by etching the matrix.

6. A method of making a ceramic truss core used in a ceramic composite structure, the ceramic truss core including ceramic fibers, the method comprising the steps of:
forming a ceramic truss using a plurality of ceramic composite pins, wherein the plurality of ceramic composite pins comprise ceramic fibers held in a matrix comprising a rigid ceramic; and,
removing the matrix from ends of the plurality of ceramic composite pins to expose the ceramic fibers, wherein removing is performed by pulverizing the matrix.

7. A method of making a ceramic composite structure, comprising the steps of:
fabricating a ceramic core by:
forming an array of ceramic composite pins each comprising ceramic fibers held in a rigid ceramic matrix,
surrounding portions of the array in a carrier such that ends of the ceramic composite pins protrude from the carrier, the carrier being made of ceramic fibers,
removing the rigid ceramic matrix from protruding ends of the ceramic composite pins to expose portions of the ceramic fibers,
protecting the carrier during the removal of the rigid ceramic matrix by applying a protective coating to the carrier, and
bending exposed portions of the ceramic fibers; and

bonding a facesheet to the ceramic core by bonding the facesheet to exposed, bent ends of the ceramic fibers.

8. A method of making a ceramic composite structure, comprising the steps of:
fabricating a ceramic core by:
forming an array of ceramic composite pins each comprising ceramic fibers held in a rigid ceramic matrix,
surrounding portions of the array in a carrier such that ends of the ceramic composite pins protrude from the carrier,
removing the rigid ceramic matrix from protruding ends of the ceramic composite pins to expose portions of the ceramic fibers, wherein removing is performed by etching the rigid ceramic matrix in the protruding ends of the ceramic composite pins,
bending exposed portions of the ceramic fibers; and

bonding a facesheet to the ceramic core by bonding the facesheet to exposed, bent ends of the ceramic fibers.

9. A method of making a ceramic composite structure, comprising the steps of:
fabricating a ceramic core by:
forming an array of ceramic composite pins each comprising ceramic fibers held in a rigid ceramic matrix,
surrounding portions of the array in a carrier such that ends of the ceramic composite pins protrude from the carrier,
removing the rigid ceramic matrix from protruding ends of the ceramic composite pins to expose portions of the ceramic fibers, wherein removing is performed by pulverizing the rigid ceramic matrix in the protruding ends of the ceramic composite pins,
bending exposed portions of the ceramic fibers; and

bonding a facesheet to the ceramic core by bonding the facesheet to exposed, bent ends of the ceramic fibers.

10. The method of claim 1 , further comprising:
determining a strength of a bond needed between the pins and the core, wherein the determined strength is based on a length of the ends; and
cutting the pins such that the ends of the pins are of the length to achieve the needed strength of the bond.

11. The method of claim 10 , wherein the pins include a diameter and the length is four or five times the diameter.

12. The method of claim 1 , wherein the rigid ceramic binder is made of a material that tailors strength and brittleness of the pins.

13. The method of claim 12 , wherein the material includes a low temperature epoxy overcoated with a ceramic slurry.

Assignees

• Keith William P
• Chakrabarti Buddhadev
• Lehman Leanne
• Boeing Co

Inventors

• Keith William P
• Chakrabarti Buddhadev
• Lehman Leanne

Classifications

• B32B9/005

  comprising one layer of ceramic material, e.g. porcelain, ceramic tile (layered products with at least two ceramic layers composed mainly of ceramic B32B18/00) · CPC title

• B32B5/245

  another layer next to it being a foam layer · CPC title

• B32B2605/08

  Cars · CPC title

• B32B2307/306

  Resistant to heat · CPC title

• B32B2605/18

  Aircraft · CPC title