Process and formulation to join ceramic forms while maintaining structural and physical characteristics across the bond surface

Patent metadata

Field	Value
Publication number	US-11718731-B2
Application number	US-202016828527-A
Country	US
Kind code	B2
Filing date	Mar 24, 2020
Priority date	Dec 30, 2014
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

A ceramic bonding material including at least one fibrous material, a flux agent and a thickening agent wherein the ceramic bonding material fired at a set temperature to bond the two adjacent substrate faces.

First claim

What is claimed is:

1. A method for forming a cured ceramic structure comprising the steps of:
(a) applying a bonding material to at least one bonding surface selected from a first bonding surface of a first substrate piece and a second bonding surface of a second substrate piece,
wherein the bonding material consists off
chopped fibers,
from about 0.05 to about 1.0 wt % of a fluxing agent selected from the group consisting of sodium carbonate, boron carbide, lithium metaborate, cadmium borate, cadmium borosilicate, bismuth oxide, lithium tetraborate, lead borosilicate, and combinations thereof, and a thickening agent wherein the thickening agent is a starch, a vegetable gum, a sugar, a protein, pectin, gelatin, cellulosic material or a combination thereof;

(b) joining the first bonding surface and the second bonding surface such that the bonding material is positioned between the first bonding surface and the second bonding surface to form a ceramic structure including an uncured bonding material; and
(c) heating the ceramic structure at a temperature of from about 1,000° C. to about 1,600° C. for a time sufficient to form a ceramic structure including a cured bonding material.

2. The method of claim 1 wherein at least one bonding surface is pretreated to form a pretreated bonding surface after which the bonding material is applied to the pretreated bonding surface.

3. The method of claim 1 wherein steps (a) and (b) are repeated to form a ceramic structure having more than two substrate pieces.

4. The method of claim 1 wherein the chopped fibers an average length of from about 1/16th of an inch to about ½ of an inch.

5. The method of claim 4 wherein the chopped fibers are aluminum borosilicate.

6. The method of claim 1 wherein the chopped fibers are is selected from fibers of silica (SiO 2 ), alumina (Al 2 O 3 ), zirconium oxide (ZrO 2 ), titanium oxide (TiO 2 ), aluminum silicate (Al—Si-oxide), aluminum borosilicate—with or without an alkali metal, carbon, borosilicate, silicon nitride (SiN) or silicon carbide (SiC) and combinations of these fibers.

7. The method of claim 1 wherein the chopped fibers are present in the bonding material before it is cured in an amount ranging from about 50 wt % to about 90 wt %.

8. The method of claim 1 wherein the fluxing agent is lithium metaborate.

9. The method of claim 1 wherein the thickening agent is a cellulosic material synthetic thickening agent and combinations thereof.

10. The method of claim 1 wherein the thickening agent is present in the bonding material before it is cured in an amount ranging from greater than about 0 wt % to 10 wt %.

11. The method of claim 1 wherein the first bonding surface and the second bonding surface each comprise ceramic foam.

12. The method of claim 1 , wherein the bonding material consists of an aqueous admixture of:
from about 50 wt % to about 90 wt % of chopped aluminum borosilicate fibers having an average length of from about 1/16th of an inch to about ½ of an inch;
from about 0.05 to about 1.0 wt % of lithium melaborate;
from greater than about 0 wt % to about 10 wt % of a thickening agent.

13. The method of claim 1 wherein the fluxing agent is sodium carbonate.

14. The method of claim 1 wherein the fluxing agent is boron carbide.

15. The method of claim 1 wherein the fluxing agent is cadmium borate.

16. The method of claim 1 wherein the fluxing agent is cadmium borosilicate.

17. The method of claim 1 wherein the fluxing agent is bismuth oxide.

18. The method of claim 1 wherein the fluxing agent is lithium tetraborate.

19. The method of claim 1 wherein the fluxing agent is lead borosilicate.

20. A method for forming a cured ceramic structure comprising the steps of:
(a) applying a bonding material to at least one bonding surface selected from a first bonding surface of a first substrate piece and a second bonding surface of a second substrate piece,
wherein the bonding material consists of;
chopped fibers,
from about 0.05 to about 1.0 wt % of a fluxing agent that is one or more of sodium carbonate, boron carbide, lithium metaborate, cadmium borate, cadmium borosilicate, bismuth oxide, lithium tetraborate, or lead borosilicate, and
a thickening agent wherein the wherein the thickening agent is a starch, a vegetable gum, a sugar, a protein, pectin, gelatin, or a combination thereof;

(b) joining the first bonding surface and the second bonding surface such that the bonding material is positioned between the first bonding surface and the second bonding surface to form a ceramic structure including an uncured bonding material; and
(c) heating the ceramic structure for a time sufficient to form a ceramic structure including a cured bonding material.

21. The method of claim 20 , wherein the chopped fibers are selected from fibers of silica (SiO 2 ), alumina (Al 2 O 3 ), zirconium oxide (ZrO 2 ), titanium oxide (TiO 2 ), aluminum silicate (Al—Si-oxide), aluminum borosilicate—with or without an alkali metal, carbon, borosilicate, silicon nitride (SiN) or silicon carbide (SiC) and combinations of these fibers.

22. The method of claim 20 , wherein the chopped fibers are aluminum borosilicate.

23. The method of claim 20 , wherein the chopped fibers are present in the bonding material before in an amount ranging from about 50 wt % to about 90 wt %.

24. The method of claim 20 , wherein the thickening agent is present in the bonding material before it is cured in an amount ranging from greater than about 0 wt % to 10 wt %.

Assignees

• Boeing Co

Inventors

• Crooks Tab H
• Muench Maryann S

Classifications

• C08K3/38 Primary

  Boron-containing compounds · CPC title

• B32B5/32 Primary

  at least two} layers being foamed {and next to each other · CPC title

• B32B7/027

  Thermal properties · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• B32B18/00

  Layered products essentially comprising ceramics, e.g. refractory products · CPC title