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US3896019A
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Method of forming beta-alumina articles
Assignee: General Electric Co
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Filing: 1973-10-04
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Granted: 1975-07-22
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Expires: 1993-10-04
Abstract
Abstract A method of forming beta-alumina articles includes sintering beta-alumina greenware between 1650* and 1825*C in a preheated oxygen oxidizing atmosphere at a controlled passage rate from one-half to four inches per minute. Such articles are useful as containers for sodium and as solid electrolytes in sodium-sulfur and sodium-halogen batteries.
Inventors
- 👤 Stephan P Mitoff
- 👤 Robert W Powers
- 👤 Randall N King
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:00
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/113; H; H01; H01M; H01M10/00; H01M10/36; H01M10/39; H01M10/3909; H01M10/3918; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
96 words
A METHOD OF FORMNG A BETA-ALUMINA ARTICLE WHICH COMPRISES PROVIDING A PLURALITY OF BETA-ALUMNA PARTICLES THE MAJORIY OF WHICH HAVE A DIAMETER FROM SUBMICRON SIZE TO 5 MICRONS, FORMING THE PARTICLES INO GREENWARE WITH A DENSITY OF AT LEAST 40 PERCENT OF THE THEORETICAL DENSITY, AND PASSING THE GREENWARE AT ATEMPERATURE BETWEEN 1650* AND 1825*C THROUGH A PREHEATED OXYGEN OXIDIZING ATMOSPHERE AND AT A CONTROLLED PASSAGE RATE OF FROM ONE-HALF TO FOUR INCHES PER MINUTE WITH GREENWARE EXPOSURE TO SUCH TEMPERATURE RANGING FROM ABOUT 6 MINUTES TO 3/4 MINUTE RESULTING IN A DENSE, SINTERED BETA-ALUMINA ARTICLE.
Claim 2
Independent Claim
96 words
A METHOD OF FORMNG A BETA-ALUMINA ARTICLE WHICH COMPRISES PROVIDING A PLURALITY OF BETA-ALUMNA PARTICLES THE MAJORIY OF WHICH HAVE A DIAMETER FROM SUBMICRON SIZE TO 5 MICRONS, FORMING THE PARTICLES INO GREENWARE WITH A DENSITY OF AT LEAST 40 PERCENT OF THE THEORETICAL DENSITY, AND PASSING THE GREENWARE AT ATEMPERATURE BETWEEN 1650* AND 1825*C THROUGH A PREHEATED OXYGEN OXIDIZING ATMOSPHERE AND AT A CONTROLLED PASSAGE RATE OF FROM ONE-HALF TO FOUR INCHES PER MINUTE WITH GREENWARE EXPOSURE TO SUCH TEMPERATURE RANGING FROM ABOUT 6 MINUTES TO 3/4 MINUTE RESULTING IN A DENSE, SINTERED BETA-ALUMINA ARTICLE.
Claim 3
Dependent Claim
14 words
A dense, sintered beta-alumina article made in accordance with the method of claim 1.
Claim 4
Independent Claim
145 words
A method of forming a beta-alumina article which comprises a suspension of beta-alumina particles the majority of which have a diameter from submicron size to 2 microns in an organic fluid having a dielectric constant at 25*C of from 12 to 24, electrophoretically depositing the beta-alumina particles from the suspensions onto a charged electrode in a DC electric field of from 100 to 10,000 volts per centimeter as greenware with a density of at least 40 percent of the theoretical density, drying the greenware on the electrode, removing the greenware from the electrode, and passing the greenware at a temperature between 1650* and 1825*C through a preheated oxygen oxidizing atmosphere and at a controlled passage rate of from one-half to four inches per minute with greenware exposure to such temperature ranging from about 6 minutes to 3/4 minute resulting in a dense, sintered beta-alumina article.
Claim 5
Independent Claim
145 words
A method of forming a beta-alumina article which comprises a suspension of beta-alumina particles the majority of which have a diameter from submicron size to 2 microns in an organic fluid having a dielectric constant at 25*C of from 12 to 24, electrophoretically depositing the beta-alumina particles from the suspensions onto a charged electrode in a DC electric field of from 100 to 10,000 volts per centimeter as greenware with a density of at least 40 percent of the theoretical density, drying the greenware on the electrode, removing the greenware from the electrode, and passing the greenware at a temperature between 1650* and 1825*C through a preheated oxygen oxidizing atmosphere and at a controlled passage rate of from one-half to four inches per minute with greenware exposure to such temperature ranging from about 6 minutes to 3/4 minute resulting in a dense, sintered beta-alumina article.
Claim 6
Dependent Claim
33 words
In a method of forming a beta-alumina article as in claim 3, in which the suspension consists of beta-alumina and an organic fluid, and the oxidizing atmosphere temperature is between 1650* and 1750*C.
Claim 7
Dependent Claim
28 words
A method of forming a beta-alumina article as in claim 3, in which the suspension contains 1.0% magnesia, and the oxidizing atmosphere temperature is between 1700* and 1750*C.
Claim 8
Dependent Claim
32 words
In a method of forming a beta-alumina article as in claim 3, in which the suspension contains 1.0% magnesia and 0.5% yttria, and the oxidizing atmosphere temperature is between 1725* and 1800*C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |