Surface protection of porous ceramic bodies

• US 20030032545A1
• Filed: 08/10/2001
• Published: 02/13/2003
• Est. Priority Date: 08/10/2001
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: DiChiara, Robert A. Jr.
• Granted Patent: US 6,919,103 B2
• Time in Patent Office: Days
• US Class Current: 501/87
• CPC Class Codes: C04B 35/00 Shaped ceramic products characterised by their composition porous ceramic products C04B38/00; ceramic articles characterised by particular shape, see the relevant classes, e.g. linings for casting ladles, tundishes, cups or the like B22D41/02; ceramic substrates for microelectronic semi-conductors H01L23/15; Ceramics compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides other than as macroscopic reinforcing agents C22C; shaping of ceramics B28B; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products chemical preparation of powders of inorganic compounds C01; infiltration of sintered ceramic preforms with molten metal C04B41/51
• CPC Class Codes: C04B 38/00 Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof treating slag with gases or gas generating material C04B5/06 ; expanded graphite C04B35/536
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4539 as a emulsion, dispersion or suspension
• CPC Class Codes: C04B 41/5006 Boron compounds
• CPC Class Codes: C04B 41/5037 Clay, Kaolin
• CPC Class Codes: C04B 41/5058 Boron carbide
• CPC Class Codes: C04B 41/5089 Silica sols, alkyl, ammonium or alkali metal silicate cements
• CPC Class Codes: C04B 41/87 Ceramics

Abstract

A porous ceramic body protected by a damage resistant hardened surface, and a method for preparing the surface hardened ceramic body. The ceramic body is protected by applying to the surface a slurry composition containing a binding agent, particles of a ceramic material, at least one boron containing compound, and a solvent. The inclusion of at least one boron containing compound in the slurry provides for hardened surfaces that are stable to higher temperatures as compared to those of the prior art.

Claims

1. A slurry composition comprising solids and a solvent, wherein the solids comprise:

a binding agent;

a ceramic material; and

at least one boron containing compound.

2. A slurry composition according to claim 1, wherein the ceramic material includes cordierite.

3. A slurry composition according to claim 1, wherein the solvent comprises water.

4. A slurry composition according to claim 1, wherein the boron containing compound is selected from the group consisting of boron carbide, boron butoxide, boron nitride, boron nitrate, and mixtures thereof.

5. A slurry composition according to claim 1, wherein the solids have an average particle size of less than about 2.0 micrometers.

6. A slurry composition according to claim 1, wherein the ceramic powder comprises cordierite, the boron containing compound is selected from the group consisting of boron carbide, boron nitride, boron butoxide, and mixtures thereof, and the solvent comprises water.

7. A method of protecting a surface of a ceramic body, comprising:

applying to the surface a slurry composition according to claim 1.

8. A method of protecting a surface of a ceramic body, comprising the step of applying a slurry composition according to claim 6 to the surface of the body.

9. A method for protecting a surface of a porous ceramic body, comprising the steps of:

applying to the surface a slurry composition comprising;

a binding agent;

a ceramic material different from the material of the ceramic body;

at least one boron containing compound;

solvent; and

impregnating the slurry into the pores of the ceramic body.

10. A method according to claim 9, wherein the binding agent comprises silica particles.

11. A method according to claim 9, wherein the solvent comprises water.

12. A method according to claim 9, wherein the ceramic material comprises cordierite.

13. A method according to claim 9, further comprising the steps of:

drying the slurry in the pores of the ceramic body; and

firing the dried slurry in the pores.

14. A method according to claim 9, wherein the ceramic body is provided in the form of a tile.

15. A ceramic body having at least one protected surface, prepared by a process comprising the step of:

applying to the surface a slurry composition comprising;

a binding agent comprising silica particles;

a ceramic material different from that of the ceramic body;

at least one boron containing compound; and

solvent.

16. A ceramic body according to claim 15, wherein the solvent comprises water.

17. A ceramic body according to claim 15, wherein the ceramic material comprises cordierite.

18. A ceramic body according to claim 15, wherein the boron containing compound is selected from the group consisting of boron carbide, boron nitride, boron butoxide, and mixtures thereof.

19. A ceramic body according to claim 15, wherein the ceramic body is in the form of a tile.