Patent US3620838A successfully refreshed from Google Patents.
US3620838A
Expired / Lapsed
US
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Method of densification of porous layers
Assignee: Siemens AG
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Filing: 1969-12-16
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Granted: 1971-11-16
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Expires: 1989-12-16
Abstract
Abstract Described is a method of producing thermionic converters by densifying porous tungsten layers on the surface of a uranium dioxide/molybdenum substrate. The pores of the tungsten layer are filled by pyrolytically precipitating tungsten from the vapor phase from tungsten hexacarbonyl, W(CO)6, at a substrate temperature of about 1,200* C., into the pores and onto the surface of the substrate. The CO gas developing during the densification process is withdrawn.
Inventors
- 👤 Martin Peehs
- 👤 Friedrich Wendler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:53
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/06; C23C16/16; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9335; Y10S428/938; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12146
Claims Analysis
Total Claims: 0
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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) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |