Bonding dissimilar ceramic components

Patent metadata

Field	Value
Publication number	US-10894747-B2
Application number	US-201815984667-A
Country	US
Kind code	B2
Filing date	May 21, 2018
Priority date	Dec 30, 2014
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

Adhesive compositions and methods for bonding materials with different thermal expansion coefficients is provided. The adhesive is formulated using a flux material, a low flux material, and a filler material, where the filler material comprises particulate from at least one of the two components being bonded together. A thickening agent can also be used as part of the adhesive composition to aid in applying the adhesive and establishing a desired bond thickness. The method of forming a high strength bond using the disclosed adhesive does not require the use of intermediary layer or the use of high cure temperatures that could damage one or both of the components being bonded together.

First claim

What is claimed:

1. A composite object comprising:
a first component comprising a ceramic having a first coefficient of thermal expansion and a second component comprising a ceramic having a second coefficient of thermal expansion that is different than the first coefficient of thermal expansion;
a formed bond adhering the first and second components together, the formed bond resulting from heat treating an adhesive comprising:
a) a particulate having the same chemical composition as the first component, wherein the particulate is selected from one or more of glass coated ceramic matrix composites and metal matrix ceramics;
b) a fluxing agent; and
c) a low flux material,

wherein heating of the adhesive causes a chemical composition change to at least one bonding surface of either the first or second components.

2. The composite of claim 1 where the formed bond between the first and second components establishes a coefficient of thermal expansion transition region between the first and second components.

3. The composite object of claim 1 where the percent by weight of the particulate of the adhesive is determined by the difference between the coefficient of thermal expansion of the first component and the coefficient of thermal expansion of the second component.

4. The composite object of claim 1 where the fluxing agent comprises lithium metaborate.

5. The composite object of claim 1 where the low flux material comprises zirconium oxide.

6. The composite object of claim 1 wherein the adhesive further comprises water and a thickening agent.

7. The composite object of claim 6 where the thickening agent comprises chemically modified cellulose.

8. The composite object of claim 1 where the particulate further comprises particles having the same chemical composition as the second component.

9. The composite object of claim 1 , wherein the fluxing agent is selected from lithium metaborate, sodium carbonate, boron carbide, high borate glass, lime, alkaline ash, and mixtures thereof.

10. The composite object of claim 1 , wherein the low flux material is selected from zirconia oxide, silicon nitride, silicon carbide, aluminates, silicates, alumino-silicates, titanates, zirconates, and mixtures thereof.

11. A composite object comprising:
a first component comprising a ceramic and a second component comprising a ceramic;
a formed bond adhering the first and second components together, the formed bond resulting from heat treating an adhesive comprising:
a) a particulate selected from one or more of glass coated ceramic matrix composites and metal matrix ceramics;
b) a fluxing agent; and
c) a low flux material.

12. The composite object of claim 11 , wherein the fluxing agent is selected from lithium metaborate, sodium carbonate, boron carbide, high borate glass, lime, alkaline ash, and mixtures thereof.

13. The composite object of claim 11 , wherein the low flux material is selected from zirconia oxide, silicon nitride, silicon carbide, aluminates, silicates, alumino-silicates, titanates, zirconates, and mixtures thereof.

14. The composite object of claim 11 where the fluxing agent comprises lithium metaborate.

15. The composite object of claim 11 where the low flux material comprises zirconium oxide.

16. The composite object of claim 11 wherein the adhesive further comprises water and a thickening agent.

17. The composite object of claim 16 where the thickening agent comprises chemically modified cellulose.

18. The composite object of claim 17 where the chemically modified cellulose is methyl cellulose.

19. The composite object of claim 11 where the particulate comprises particles having the same chemical composition as the first component.

20. The composite object of claim 19 where the particulate further comprises particles having the same chemical composition as the second component.

Assignees

• Boeing Co

Inventors

• Crooks Tab Hunter
• Muench Maryann S

Classifications

• B32B7/027

  Thermal properties · CPC title

• C04B2237/60

  Forming at the joining interface or in the joining layer specific reaction phases or zones, e.g. diffusion of reactive species from the interlayer to the substrate or from a substrate to the joining interface, carbide forming at the joining interface · CPC title

• C04B2237/401

  Cermets · CPC title

• C04B2235/656

  characterised by specific heating conditions during heat treatment · CPC title

• C04B37/005 Primary

  consisting of glass or ceramic material · CPC title