US4098612A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transparent yttria ceramics and method for producing same
Assignee: Osram Sylvania Inc
•
Filing: 1977-07-11
•
Granted: 1978-07-04
•
Expires: 1997-07-11
Abstract
Abstract An article of manufacture is provided comprising a substantially transparent high density polycrystalline yttria-base body consisting essentially of yttria and from about 0.01 to 5 wt. % alumina. A method for preparing the transparent yttria doped with alumina is also provided comprising admixing alumina or a precursor thereof with yttria or a precursor thereof, drying the admixed powders, calcining the admixed powders and pressing the calcined powders into a desired shape and thereafter sintering the shaped powder for about 1/4 to 6 hours at a temperature above the eutectic temperature at a sufficiently low oxygen atmosphere to prevent oxidative contaminants.
Inventors
- 👤 William H. Rhodes
- 👤 F. Joseph Reid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:57
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/50; C04B35/505; H; H01; H01J; H01J5/00; H01J5/02; H01J5/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
26 words
An article of manufacture comprising a substantially transparent, high density polycrystalline yttria-based body consisting essentially of yttria and from about 0.01 to 5 wt. % alumina.
Claim 2
Dependent Claim
26 words
An article of manufacture comprising a substantially transparent, high density polycrystalline yttria-based body consisting essentially of yttria and from about 0.01 to 5 wt. % alumina.
Claim 3
Dependent Claim
18 words
An article of manufacture as defined in claim 1 containing from about 0.05 to 0.25 wt. % alumina.
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) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |