Claims
- 1. A method for producing an aluminum nitride ceramic which comprises:
- (a) obtaining a powder of aluminum nitride;
- (b) contacting said powder with gel of a metallic compound that forms a low contact angle with said powder at the sintering step (d) and wherein said metallic compound include a member selected from the group of cobalt, nickel and mixtures thereof and at least one alloying member selected from the group of transition elements and rare earth elements;
- removing solvents and any organic material obtained from the composition from step (b);
- (d) sintering the composition from step (c) to thereby produce said ceramics.
- 2. The method of claim 1 wherein said powder has a particle size of about 1 .mu. to about 12 .mu..
- 3. The method of claim 1 wherein the average particle size of said powder is about 2 microns.
- 4. The method of claim 1 wherein the metallic compound produced from the gel layer forms a contact angle of about 0.degree. to about 40.degree. with said powder at the sintering step.
- 5. The method of claim 1 wherein said gel is applied as a coating to said powder or was intimately mixed as a second phase in the composite powder.
- 6. The method of claim 1 wherein said powder is dispersed in a non-aqueous medium containing organo-metallic compound capable of forming a gel and then converting the dispersion into a gel.
- 7. The method of claim 1 wherein said powder comprises at least about 90% by weight of the combined solids from said powder and metallic compound.
- 8. The method of claim 1 wherein said powder comprises about 90% to about 99.5% by weight of the combined solids from said powder and metallic compound.
- 9. The method of claim 1 wherein said metallic compound is an alloy of nickel and an alloying metal selected from the group of yttrium, lanthanum, Sc, Ce, hafnium, zirconium, titanium.
- 10. The method of claim 9 wherein said alloy contains about 90% to about 30% of nickel and about 10% to about 70% by weight of said alloying metal.
- 11. The method of claim 9 wherein said metallic compound is an alloy of nickel and yttrium.
- 12. The method of claim 1 wherein said sintering is carried out at temperatures of about 1500.degree. C. to about 1900.degree. C.
- 13. The method of claim 1 wherein said sintering is carried out under a reducing atmosphere.
- 14. The method of claim 1 wherein said sintering is carried out in the presence of ammonia.
- 15. The method of claim 1 wherein said sintering is a pressureless sintering.
- 16. The method of claim 1 wherein said sintering is completed in about 1/2 hour to about 2 hours.
- 17. The method of claim 1 wherein said sintering is hot pressing.
Parent Case Info
This application is a continuation of Ser. No. 193,023, filed on May 12, 1988, now abandoned.
US Referenced Citations (10)
Non-Patent Literature Citations (1)
Entry |
Hlavac, J., "The Technology of Glass and Ceramics", Elsevier Pub., N.Y., (1983), p. 297. |
Continuations (1)
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Number |
Date |
Country |
Parent |
193023 |
May 1988 |
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