Patent US3767745A successfully refreshed from Google Patents.
US3767745A
Expired / Lapsed
US
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Hot pressing ceramic oxides to transparency by heating in isothermal increments
Assignee: United States Department of the Army
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Filing: 1972-02-07
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Granted: 1973-10-23
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Expires: 1992-02-07
Abstract
Abstract A PRESSURE SINTERING PROCESS FOR THE FABRICATION OF ULTRAFINE GRAINED CERAMICS HAVING IMPROVED STRENGTH AND ENHANCED TRANSPARENCYT COMPRISING THE COLD COMPRESSING OF A CERAMIC OXIDE POWDER HAVING A CUBIC CRYSTAL STRUCTURE, REMOVING UNDESIRED GASES, RAISING TO A TEMPERATURE AT WHICH FULL DENSITY OF THE COMPACT CAN BE OBTAINED IN ISOTHERMAL INCREMENTS OF ABOUT 50* UNDER ELEVATED PRESSURES WHILE MAINTAINING THE TEMPERATURE AT EACH INCREMENTAL INCREASE FOR A PERIOD OF ABOUT 50-60 MINUTES, AND RECOVERING THE PRODUCT. MATERIALS HAVING A CUBIC CRYSTAL STRUCTURE SUCH AS MGAL2O4, LIAL5O8, Y3AL5O12, MGO AND ZNO ARE SUITABLE FOR HOT PRESSING IN THIS PROCESS.
Inventors
- 👤 G Gazza
- 👤 S Dutta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:05
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/44; C04B35/443; C04B35/03; C04B35/04; C04B35/053; C04B35/453; C04B35/622; C04B35/626; C04B35/62605; C04B35/62645; C04B35/62655; C04B35/64; C04B35/645; C01; C01P; C01P2002/00; C01P2002/30; C01P2002/32; C01P2004/00; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/10; C01P2006/60; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3201; C04B2235/3203; C04B2235/3224; C04B2235/3225; C04B2235/3284; C04B2235/50; C04B2235/52; C04B2235/528; C04B2235/54; C04B2235/5418; C04B2235/5436; C04B2235/60; C04B2235/608; C04B2235/65; C04B2235/656; C04B2235/6562; C04B2235/6567; C04B2235/658; C04B2235/6581; C04B2235/66; C04B2235/661; C04B2235/70; C04B2235/74; C04B2235/76; C04B2235/762; C04B2235/78; C04B2235/785; C04B2235/96; C04B2235/9646; C04B2235/9653
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |