Patent US3870435A successfully refreshed from Google Patents.
Patent US3011870A successfully refreshed from Google Patents.
US3011870A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing virtually perfect alumina crystals
Assignee: Union Carbide Corp
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Filing: 1958-09-05
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Granted: 1961-12-05
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Expires: 1978-09-05
Abstract
No abstract record available.
Inventors
- 👤 Watt W Webb
- 👤 William A Wissler
- 👤 William D Forgeng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:07
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/005; C30B29/00; C30B29/10; C30B29/16; C30B29/20; C30B29/60; Y; Y10; Y10S; Y10S264/00; Y10S264/19
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
140 words
A METHOD FOR PRODUCING SINGLE, HIGH STRENGTH, VIRTUALLY PERFECT CRYSTALS OF ALPHA-ALUMINUM OXIDE (A-AL2O2) COMPRISING THE STEPS OF PROVIDING A REFRACTORY ARTICLE HAVING THEREON AN ALUMINUM OXIDE SUBSTRATE, INTIMATELY CONTACING SAID SUBSTRATE WITH VAPOROUS ALUMINUM OXIDE FORMED BY THE REACTION OF AN ALUMINUM SOURCE MATERIAL SELECTED FROM THE GROUP CONSISTING OF ALUMINUM AND THE ALUMINIDES OF ZIRCONIUM, HAFNIUM, VANADIUM, NIOBIUM, TANTALUM, CHROMIUM, MOLYBDENUM, AND TUNGSTEN AT A TEMPERATURE BETWEEN 1300* AND 2050*C. WITH AN ATMOSPHERE CONSISTING OF A STREAM OF HYDROGEN AT A PRESSURE OF ABOUT ONE ATMOSPHERE AND WATER VAPOR WITH A VAPOR PRESSURE TO HYDROGEN GAS PRESSURE RATIO BETWEEN 10-8 TO 1 AND 1 TO 1, WHEREBY THE VAPOROUS ALUMINUM OXIDES CONDENSES ON SAID SUBSTRATE AND DISPROPORTIONATES TO LIQUID ALUMINUM METAL AND SOLID ALUMINUM OXIDE, AND SOLID ALUMINUM OXIDE BEING FORMED AS SINGLE CRYSTALS OF ALPHA-ALUMINUM OXIDE (A-AL2O3).
Claim 2
Independent Claim
140 words
A METHOD FOR PRODUCING SINGLE, HIGH STRENGTH, VIRTUALLY PERFECT CRYSTALS OF ALPHA-ALUMINUM OXIDE (A-AL2O2) COMPRISING THE STEPS OF PROVIDING A REFRACTORY ARTICLE HAVING THEREON AN ALUMINUM OXIDE SUBSTRATE, INTIMATELY CONTACING SAID SUBSTRATE WITH VAPOROUS ALUMINUM OXIDE FORMED BY THE REACTION OF AN ALUMINUM SOURCE MATERIAL SELECTED FROM THE GROUP CONSISTING OF ALUMINUM AND THE ALUMINIDES OF ZIRCONIUM, HAFNIUM, VANADIUM, NIOBIUM, TANTALUM, CHROMIUM, MOLYBDENUM, AND TUNGSTEN AT A TEMPERATURE BETWEEN 1300* AND 2050*C. WITH AN ATMOSPHERE CONSISTING OF A STREAM OF HYDROGEN AT A PRESSURE OF ABOUT ONE ATMOSPHERE AND WATER VAPOR WITH A VAPOR PRESSURE TO HYDROGEN GAS PRESSURE RATIO BETWEEN 10-8 TO 1 AND 1 TO 1, WHEREBY THE VAPOROUS ALUMINUM OXIDES CONDENSES ON SAID SUBSTRATE AND DISPROPORTIONATES TO LIQUID ALUMINUM METAL AND SOLID ALUMINUM OXIDE, AND SOLID ALUMINUM OXIDE BEING FORMED AS SINGLE CRYSTALS OF ALPHA-ALUMINUM OXIDE (A-AL2O3).
Claim 3
Dependent Claim
34 words
NEEDLE-LIKE HIGH STRENGTH, VIRTUALLY PERFECT SINGLE CRYSTALS OF ALPHA-ALUMINUM OXIDE (A-AL2O3) HAVING A HEXAGONAL CROSS-SECTION AND A LENGTH FROM ABOUT 1 TO 30 MM. LONG AND A WIDTH FROM ABOUT 3 TO 50 MICRONS.
Claim 4
Dependent Claim
34 words
NEEDLE-LIKE HIGH STRENGTH, VIRTUALLY PERFECT SINGLE CRYSTALS OF ALPHA-ALUMINUM OXIDE (A-AL2O3) HAVING A HEXAGONAL CROSS-SECTION AND A LENGTH FROM ABOUT 1 TO 30 MM. LONG AND A WIDTH FROM ABOUT 3 TO 50 MICRONS.
References Cited (Backward Citations)
GB165052A
Cited
US2758011A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-12-04 | 1965-06-05 | 1965-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-12-04 | 1969-06-05 | 1969-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-12-04 | 1973-06-05 | 1973-12-05 | $7700.00 | Window Closed / Lapsed |