Method of producing self-supporting aluminum titanate composites and products relating thereto

• US 5,139,979 A
• Filed: 05/06/1991
• Issued: 08/18/1992
• Est. Priority Date: 01/30/1989
• Status: Expired due to Fees

• Current Assignee: Lanxide Technology Company, LP
• Original Assignee: Lanxide Technology Company, LP
• Inventors: Anderson, Edward M., Johnson, Thomas A.
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): HOLLENBECK, SUSAN
• Application Number:
  US07/697,741
• Time in Patent Office: 470 Days
• Field of Search: 501/127, 501/153, 501/134, 501/135, 501/136, 164/91, 164/101
• US Class Current: 501/134
• CPC Class Codes: C04B 2111/00405 Materials with a gradually increasing or decreasing concentration of ingredients or property from one layer to another
• CPC Class Codes: C04B 35/478 based on aluminium titanates
• CPC Class Codes: C04B 35/62222 obtaining ceramic coatings coating of mortars, concrete, artificial or natural stone or ceramics C04B41/45; laminated ceramic products B32B18/00; coating metallic materials C23; coating of glass C03C17/00, applying ceramic coatings on silicon for semi-conductor purposes H01L
• CPC Class Codes: C04B 35/652 Directional oxidation or solidification, e.g. Lanxide process
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence

Abstract

The present invention relates, generally, to a self-supporting porous ceramic composite body and to methods for producing such articles to net or near net shape, which bodies exhibit superior thermal and mechanical properties. The invention also relates to the manufacture of ceramic-metal composite bodies which have ceramic articles incorporated therein.

Claims

1. A method for producing a thermal shock resistant, thermally insulating and compliant article comprising:

(a) mixing a powder comprising a parent metal with at least one material selected from the group consisting of aluminum titanate and aluminum titanate precurors;

(b) adding a stabilization aid material;

(c) forming a green body from the mixture of step (b); and

(d) oxidizing and sintering said green body to form an article comprising aluminum titanate.

2. A method according to claim 1, wherein said parent metal comprises aluminum.

3. A method according to claim 1, wherein the stabilization aid comprises at least one material selected from the group consisting of chrome ore, ilmenite, SiO₂, MgO and Fe₂ O₃.

4. A method according to claim 1, further comprising forming said green body by a method selected from the group consisting of hot pressing, slip casting, injection molding, sediment casting, and extrusion.

5. A method according to claim 4, wherein said method comprises slip casting and further comprises controlling the pH of the slip during ball milling of the slip.

6. A method according to claim 1, further comprising sintering said green body at a temperature of from about 1300°

C. through at least 1500°

C.

7. A method according to claim 6, wherein said oxidizing is continued for a time sufficient to form at least some oxidation reaction product from said parent metal such that said parent metal provides porosity in the sintered body.

8. A method according to claim 1, wherein said aluminum titanate precursors comprise at least one material selected from the group consisting of Al₂ O₃, TiO₂, Al, Ti and alloys of Al and Ti.

9. A method according to claim 7, wherein said parent metal comprises an aluminum alloy comprising at least one material selected from the group consisting of Zn, Cu, Si, Fe and Mg.

10. A method according to claim 1, further comprising casting a molten metal around of said sintered article aluminum titanate.

11. A method according to claim 10, wherein said molten metal comprises at least one material selected from the group consisting of aluminum, iron and alloys thereof.

12. A product produced according to the method of claim 1.

13. A product produced according to the method of claim 11.

14. The method according to claim 1, wherein said parent metal comprises at least one metal selected from the group consisting of aluminum, titanium, zirconium and tin.

15. The method according to claim 1, wherein said parent metal comprises from about 5 to about 35 weight percent of said green body.

16. The method according to claim 3, wherein said stabilizers comprises from about 5 to about 20 percent by weight of said green body.

17. The method according to claim 1, wherein said at least one material provides a sufficient quantity of material to result in about 50 to about 95 percent by weight Al₂ TiO₅ in the formed body.

18. A method for producing a porous ceramic composite which is to be at least partially surrounded by a cast metal, said method comprising:

(a) providing a powder comprising at least one parent metal selected from the group consisting of aluminum, titanium, and alloys thereof mixed with at least one material comprising a material selected from the group consisting of Al₂ TiO₅, Al₂ O₃, and TiO₂ ;

(b) adding at least one material comprising a material selected from the group consisting of chrome ore, ilmenite, SiO₂ and MgO and Fe₂ O₃ ;

(c) forming a green body using a method selected from the group consisting of hot pressing, slip casting, injection molding, dry pressing, sediment casting and extrusion; and

(d) oxidizing and sintering said green body in air at a temperature of at least 1300°

C. for at least a time sufficient to form at least some oxidation reaction product from said parent metal in order to induce porosity and to provide integrity;

thereby forming said porous ceramic composite.

19. The method according to claim 18, wherein said porous ceramic composite comprises from about 10 to about 50 percent porosity.