Patent US3232803A successfully refreshed from Google Patents.
US3232803A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemical etching of tungsten
Assignee: North American Aviation Corp
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Filing: 1963-04-16
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Granted: 1966-02-01
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Expires: 1983-04-16
Abstract
No abstract record available.
Inventors
- 👤 Gordon D Barnett
- 👤 Miller Arnold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:54
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
102 words
THE PROCESS OF ETCHING A TUNGSTEN SURFACE ON A BODY, COMPRISING THE STEPS OF PLACING SAID BODY IN A REACTION VESSEL, EVACUATING THE VESSEL TO A PREDETERMINED PRESSURE, HEATING SAID SURFACE TO A TEMPERATURE OF FROM 200 TO 1400 DEGREES C. AND WHILE MAINTAINING SAID TEMPERATURE, INTRODUCING INTO THE REACTION VESSEL A SUPPLY OF TUNGSTEN HEXAFLUORIDE TO PROVIDE A PRESSURE OF THE HEXAFLUORIDE IN THE REACTION VESSEL OF FROM 10 MICRONS TO 10 MILLIMETERS,THEREBY TO ETCH SAID TUNGSTEN SURFACE FOR REVEALING THE METALLURGICAL STRUCTURE OF A SINGLE CRYSTAL OF SAID TUNGSTEN SURFACE, SAID PREDETERMINED PRESSURE BEING LESS THAN THAT OF THE HEXAFLUORIDE.
Claim 2
Dependent Claim
102 words
THE PROCESS OF ETCHING A TUNGSTEN SURFACE ON A BODY, COMPRISING THE STEPS OF PLACING SAID BODY IN A REACTION VESSEL, EVACUATING THE VESSEL TO A PREDETERMINED PRESSURE, HEATING SAID SURFACE TO A TEMPERATURE OF FROM 200 TO 1400 DEGREES C. AND WHILE MAINTAINING SAID TEMPERATURE, INTRODUCING INTO THE REACTION VESSEL A SUPPLY OF TUNGSTEN HEXAFLUORIDE TO PROVIDE A PRESSURE OF THE HEXAFLUORIDE IN THE REACTION VESSEL OF FROM 10 MICRONS TO 10 MILLIMETERS,THEREBY TO ETCH SAID TUNGSTEN SURFACE FOR REVEALING THE METALLURGICAL STRUCTURE OF A SINGLE CRYSTAL OF SAID TUNGSTEN SURFACE, SAID PREDETERMINED PRESSURE BEING LESS THAN THAT OF THE HEXAFLUORIDE.
References Cited (Backward Citations)
US3171755A
Cited
US3139658A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-01-31 | 1969-08-02 | 1970-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-31 | 1973-08-02 | 1974-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-31 | 1977-08-02 | 1978-02-01 | $7700.00 | Window Closed / Lapsed |