Patent US3594444A successfully refreshed from Google Patents.
Patent US4096025A successfully refreshed from Google Patents.
US4096025A
Expired / Lapsed
US
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Method of orienting seed crystals in a melt, and product obtained thereby
Assignee: United States Department of the Army
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Filing: 1975-06-23
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Granted: 1978-06-20
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Expires: 1995-06-23
Abstract
Abstract A method for the production of improved, transparent single crystals having a corundum structure under conditions of minimum thermal strain, comprising the optimum orientation of growth planes of a seed crystal in a melt substantially parallel to the vertical side wall means of a crucible, and heating and subsequent cooling the melt, thereby nucleating on the seed crystal.
Inventors
- 👤 Jarda L. Caslavsky
- 👤 Frederick Schmid
- 👤 Charles P. Gazzara
- 👤 Dennis J. Viechnicki
- 👤 James W. McCauley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:48
CPC Classifications
C; C30; C30B; C30B17/00; C30B11/00; C30B11/14; C30B29/00; C30B29/10; C30B29/16; C30B29/20; Y; Y10; Y10S; Y10S117/00; Y10S117/901; Y10S117/902
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
159 words
In a method for the production of a large transparent single crystal of corundum having a hexagonal structure comprising the melting of said material in a crucible having a generally vertical wall and a horizontal bottom, the improvement comprising: cutting a seed crystal such that it has six growth planes (0112), (1102), (1012), (0112), (1102), and (1012); orienting said growth planes (0112) and (0112) of said seed crystal such that they are at an angle of about 7° to the horizontal bottom of said crucible, and said other growth planes (1102), (1012), (1102), and (1012) of said seed crystal are oriented substantially parallel to the generally vertical wall of said crucible; melting said seed crystal to a substantially hemispherical shape; and cooling said seed crystal and said material such that said material nucleates and grows in a substantially hemispherical fahsion and assumes the crystallographic orientation of said seed crystal which process minimizes the thermal strain on the single crystal.
Claim 2
Dependent Claim
159 words
In a method for the production of a large transparent single crystal of corundum having a hexagonal structure comprising the melting of said material in a crucible having a generally vertical wall and a horizontal bottom, the improvement comprising: cutting a seed crystal such that it has six growth planes (0112), (1102), (1012), (0112), (1102), and (1012); orienting said growth planes (0112) and (0112) of said seed crystal such that they are at an angle of about 7° to the horizontal bottom of said crucible, and said other growth planes (1102), (1012), (1102), and (1012) of said seed crystal are oriented substantially parallel to the generally vertical wall of said crucible; melting said seed crystal to a substantially hemispherical shape; and cooling said seed crystal and said material such that said material nucleates and grows in a substantially hemispherical fahsion and assumes the crystallographic orientation of said seed crystal which process minimizes the thermal strain on the single crystal.
Claim 3
Dependent Claim
11 words
The method according to claim 1 wherein said material is sapphire.
Claim 4
Dependent Claim
12 words
A transparent sapphire single crystal produced by the method of claim 2.
Claim 5
Dependent Claim
12 words
A transparent corundum single crystal produced by the method of claim 1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-19 | 1981-12-19 | 1982-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-19 | 1985-12-19 | 1986-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-19 | 1989-12-19 | 1990-06-20 | $7700.00 | Window Closed / Lapsed |