Patent US3732056A successfully refreshed from Google Patents.
US3732056A
Expired / Lapsed
US
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Apparatus for hot pressing oxide ceramics in a controlled oxygen atmosphere
Assignee: Motors Liquidation Co
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Filing: 1971-09-01
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Granted: 1973-05-08
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Expires: 1991-09-01
Abstract
Abstract An improved hot press apparatus for compacting oxide ceramic powders including an electrolyte die member of a solid material conductive of oxygen ions with negligible electronic conductivity, a pair of porous electrodes applied to the inner and outer surfaces of the electrolyte die member, and a resistance heater for bringing the die member to hot press temperature is disclosed. Application of a potential to the electrodes develops a voltage across the electrolyte die member whereby oxygen molecules at the outer surface are adsorbed into the electrolyte die member, pass therethrough as oxygen ions, and are desorbed at the inner surface thereof to provide an oxygen atmosphere in the area where pressure is being applied to the oxide ceramic powder. By varying the potential applied to the electrodes the oxygen partial pressure in the die can be controlled to produce sintered oxide ceramics having improved electrical, magnetic and mechanical properties.
Inventors
- 👤 D Eddy
- 👤 G Sutherland
- 👤 A Micheli
- 👤 M Brooks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:47
CPC Classifications
B; B30; B30B; B30B15/00; B30B15/02; B30B15/022; B28; B28B; B28B3/00; B28B3/02; B28B3/025; B30B11/00; B30B11/02; B30B15/34; C; C04; C04B; C04B33/00; C04B33/32; C04B33/326; Y; Y10; Y10S; Y10S425/00; Y10S425/035
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
167 words
An apparatus for hot pressing oxide ceramic powders in the presence of a controlled oxygen atmosphere comprising, an electrolyte die member of a solid material conductive of oxygen ions with negligible electronic conductivity having inner and outer surfaces and having a mold cavity therein adapted to contain oxide ceramic powder, a first electrode contacting the outer surface of said elecTrolyte die member, a second electrode contacting the inner surface of said electrolyte die member, first and second conductors contacting said first electrode and said second electrode, respectively, for applying a potential between said first and said second electrodes to develop a voltage across said electrolyte die member, said first electrode being the cathode and said second electrode being the anode, means for heating said die member to an elevated temperature, and means for applying pressure to said die member to mold said oxide ceramic powder while said potential between said first and second electrodes is applied and while said die member is heated to said elevated temperature.
Claim 2
Independent Claim
171 words
An apparatus for hot pressing oxide ceramic powders in the presence of a controlled oxygen atmosphere comprising, a tubular electrolyte die member of a solid material conductive of oxygen ions with negligible electronic conductivity having inner and outer cylindrical surfaces, a pair of opposed cylindrical punches slidably movable within said tubular electrolyte die member defining a closed mold cavity therebetween adapted to contain oxide ceramic powder, a first electrode contacting the outer surface of said electrolyte die member, a second electrode contacting the inner surface of said electrolyte die member, first and second conductors contacting said first electrode and said second electrode, respectively, for applying a potential between said first and said second electrodes to develop a voltage across said electrolyte die member, and means for heating said die member to an elevated temperature, said opposed cylindrical punches being operative to apply pressure to mold said oxide ceramic powder while said potential between said first and second electrodes is applied and while said die member is heated to said elevated temperature.
Claim 3
Independent Claim
211 words
An apparatus for hot pressing oxide ceramic powders in the presence of a controlled oxygen atmosphere comprising, a tubular electrolyte die member of a solid material conductive of oxygen ions with negligible electronic conductivity having inner and outer cylindrical surfaces, a pair of opposed cylindrical punches slidably movable within said tubular electrolyte die member defining a closed mold cavity therebetween, adapted to contain oxide ceramic powder, a first electrode disposed as a layer in direct contact with the outer surface of said electrolyte die member, a second electrode disposed as a layer in direct contact with the inner surface of said electrolyte die member, said first and second electrode layers having a substantial portion of their surfaces directly opposing each other and having a length greater than said mold cavity, first and second conductors contacting said first electrode and said second electrode, respectively, for applying a potential between said first and said second electrodes to develop a voltage across said electrolyte die member, and means for heating said die member to an elevated temperature, said opposed cylindrical punches being operative to apply pressure to mold said oxide ceramic powder while said potential between said first and second electrodes is applied and while said die member is heated to said elevated temperature.
Claim 4
Independent Claim
225 words
An apparatus for hot pressing oxide ceramic powders in the presence of a controlled oxygen atmosphere comprising, a tubular electrolyte die member of a solid material conductive of oxygen ions with negligible electronic conductivity having inner and outer cylindrical surfaces, a pair of opposed cylindrical punches slidably movable within said tubular electrolyte die member defining a closed mold cavity therebetween adapted to contain oxide ceramic powder, a first porous, electronically conductive electrode disposed as a layer in direct contact with the outer surface of said electrolyte die member, a second porous, electronically conductive electrode disposed as a layer in direct contact with the inner surface of said electrolyte die member, said first and second electrode layers havinG a substantial portion of their surfaces directly opposing each other and having a length greater than said mold cavity, first and second conductors contacting said first electrode and said second electrode, respectively, for applying a potential between said first and said second electrodes to develop a voltage across said electrolyte die member, and means in spaced relation to said electrolyte die member for heating said die member to an elevated temperature, said opposed cylindrical punches being operative to apply pressure to mold said oxide ceramic powder while said potential between said first and second electrodes is applied and while said die member is heated to said elevated temperature.
Claim 5
Dependent Claim
56 words
The apparatus as defined in claim 5 wherein said electrolyte die member consists essentially of a major portion of zirconium oxide stabilized with a minor portion of calcium oxide, said electrodes consist essentially of platinum, and said heating means is operative to heat said die member to a temperature between about 500* C. and 1,700* C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |