Method of forming beta-alumina articles

Claim 1

A METHOD OF FORMING A BETA-ALUMINA ARTICLE WHICH COMPRIES PROVIDING A SUSPENSION CONSISTING OF BETA-ALUMINA PARTICLES THE MAJORITY OF WHICH HAVE A DIAMETER IN THE RANGE OF TO 2 MICRONS IN AN ORGANIC FLUID HAVING A DIELECTRIC CONSTANT AT 25*C OF FROM 12 TO 24, ADDING 0.05 TO 0.5 PERCENT ALUMINUM STEARATE BY WEIGHT OF THE BETAALUMINA TO THE SUSPENSION, ELECTROPHORETICALLY DEPSITING THE BEA-ALUMINA PATICLES FORM THE SUSPENSION AS A DENSE DEPOSIT ON OF A CHARGED ELECTRODE IN A DC ELECTRIC FIELD OF FROM 100 TO 10,000 VOLTS PER CENTIMETER, DRYING THE DEPOSIT ON THE ELECTRODE, REMOVING THE DEPOSIT FROM THE ELECTRODE, AND SINTERING THE DEPOSIT IN AN OXYGEN OXIDIZING SATMOSPHERE AT A TEMPERATURE BETWEEN 1700 AND 1825*C RESULTING IN A DENSE, SINTERED BETA-ALUMINA ARTICLE,

Claim 2

A METHOD OF FORMING A BETA-ALUMINA ARTICLE WHICH COMPRIES PROVIDING A SUSPENSION CONSISTING OF BETA-ALUMINA PARTICLES THE MAJORITY OF WHICH HAVE A DIAMETER IN THE RANGE OF TO 2 MICRONS IN AN ORGANIC FLUID HAVING A DIELECTRIC CONSTANT AT 25*C OF FROM 12 TO 24, ADDING 0.05 TO 0.5 PERCENT ALUMINUM STEARATE BY WEIGHT OF THE BETAALUMINA TO THE SUSPENSION, ELECTROPHORETICALLY DEPSITING THE BEA-ALUMINA PATICLES FORM THE SUSPENSION AS A DENSE DEPOSIT ON OF A CHARGED ELECTRODE IN A DC ELECTRIC FIELD OF FROM 100 TO 10,000 VOLTS PER CENTIMETER, DRYING THE DEPOSIT ON THE ELECTRODE, REMOVING THE DEPOSIT FROM THE ELECTRODE, AND SINTERING THE DEPOSIT IN AN OXYGEN OXIDIZING SATMOSPHERE AT A TEMPERATURE BETWEEN 1700 AND 1825*C RESULTING IN A DENSE, SINTERED BETA-ALUMINA ARTICLE,

Claim 6

A method of forming a beta-alumina article which comprises mixing together beta-alumina particles of a diameter larger than 20 microns with an organic liquid having a dielectric constant at 25*C of from 12 to 24, adding 0.05 to 0.5 percent aluminum stearate by weight of the beta-alumina to the mixture, adding to the mixture grinding media selected from the class consisting of zirconia and alumina, milling the mixture thereby reducing the beta-alumina particles whereby a majority of which have a diameter in the range of 1 to 2 microns thereby forming a suspension with the organic fluid, providing a first electrode for deposition, and another electrode for contact with the suspension, electrophoretically depositing the beta-alumina particles onto the first electrode in a DC electric field of fRom 100 to 10,000 volts per centimeter, drying the deposit in a free oxygen atmosphere on the electrode, removing the deposit from the electrode, and sintering the deposit in an oxygen oxidizing atmosphere at a temperature between 1700* and 1825*C resulting in a dense, sintered beta-alumina article.

Claim 7

A method of forming a beta-alumina article which comprises mixing together beta-alumina particles of a diameter larger than 20 microns with an organic liquid having a dielectric constant at 25*C of from 12 to 24, adding 0.05 to 0.5 percent aluminum stearate by weight of the beta-alumina to the mixture, adding to the mixture grinding media selected from the class consisting of zirconia and alumina, milling the mixture thereby reducing the beta-alumina particles whereby a majority of which have a diameter in the range of 1 to 2 microns thereby forming a suspension with the organic fluid, providing a first electrode for deposition, and another electrode for contact with the suspension, electrophoretically depositing the beta-alumina particles onto the first electrode in a DC electric field of fRom 100 to 10,000 volts per centimeter, drying the deposit in a free oxygen atmosphere on the electrode, removing the deposit from the electrode, and sintering the deposit in an oxygen oxidizing atmosphere at a temperature between 1700* and 1825*C resulting in a dense, sintered beta-alumina article.