US4180484A
Expired / Lapsed
US
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Ceramic component for electrodes
Assignee: United States Department of Energy
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Filing: 1978-06-14
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Granted: 1979-12-25
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Expires: 1998-06-14
Abstract
Abstract A ceramic component suitable for preparing MHD generator electrodes consists of HfO2 and sufficient Tb4O7 to stabilize at least 60 volume percent of the HfO2 into the cubic structure. The ceramic component may also contain a small amount of PrO2, Yb2O3 or a mixture of both to improve stability and electronic conductivity of the electrode. The component is highly resistant to corrosion by molten potassium seed and molten coal slag in the MHD fluid and exhibits both ionic and electronic conductivity.
Inventors
- 👤 David D. Marchant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:42
CPC Classifications
H; H01; H01B; H01B1/00; H01B1/06; H01B1/08; C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/486; H05; H05B; H05B7/00; H05B7/02; H05B7/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
47 words
An electrode for use in a MHD generator comprising: HfO 2 and a minor amount of Tb 4 O 7 , the Tb 4 O 7 being present in an amount effective to stabilize at least 60 volume percent of the HfO 2 into the cubic structure.
Claim 2
Dependent Claim
47 words
An electrode for use in a MHD generator comprising: HfO 2 and a minor amount of Tb 4 O 7 , the Tb 4 O 7 being present in an amount effective to stabilize at least 60 volume percent of the HfO 2 into the cubic structure.
Claim 3
Dependent Claim
19 words
The electrode of claim 1 wherein the Tb 4 O 7 is present from 5 to 20 mole percent.
Claim 4
Dependent Claim
15 words
The electrode of claim 2 wherein the Tb 4 O 7 is 10 mole percent.
Claim 5
Dependent Claim
53 words
The electrode of claim 1 wherein the Tb 4 O 7 is present from 3 to 10 mole percent, and the electrode also contains a rare earth oxide selected from the group consisting of PrO 2 , Yb 2 O 3 and a mixture of PrO 2 and Yb 2 O 3 .
Claim 6
Dependent Claim
33 words
The electrode of claim 4 wherein the PrO 2 is present from about 3 to 10 mole percent and the Yb 2 O 3 is present from about 2 to 10 mole percent.
Claim 7
Dependent Claim
34 words
The electrode of claim 5 wherein the component contains about 5 mole percent Tb 4 O 7 , about 5 mole percent PrO 2 and about 5 mole percent Yb 2 O 3 .
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) | 1982-12-24 | 1983-06-25 | 1983-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-24 | 1987-06-25 | 1987-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-24 | 1991-06-25 | 1991-12-25 | $7700.00 | Window Closed / Lapsed |