US3857696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Melting and casting of transitional metals and alloys
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1973-05-18
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Granted: 1974-12-31
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Expires: 1993-05-18
Abstract
Abstract A method of melting and casting a transitional metal or an alloy thereof uses an unclad thin-walled graphite crucible having a bottom opening therein in which is positioned a fusible metallic member, usually alike the charge metal in composition, to obturate the opening; charge metal is positioned in the crucible and is rapidly heated by electrical induction to a temperature above its melting temperature without substantially melting the obturating member, and thereby provides a pool of molten metal flowing onto the member to melt a pour hole therethrough through which the molten charge discharges from the crucible.
Inventors
- 👤 K Aldersley
- 👤 G Telford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:33
CPC Classifications
F; F27; F27B; F27B14/00; F27B14/08; F27B14/06; F27B14/061; H; H05; H05B; H05B6/00; H05B6/02; H05B6/22; H05B6/24; F27B14/0806; F27B2014/0812; F27B2014/0818; F27D; F27D99/00; F27D99/0001; F27D99/0006; F27D2099/0015; F27D2099/0018; F27M; F27M2001/00; F27M2001/03
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
118 words
A METHOD OF MELTING AND POURING AS A MOLTEN CHARGE A TRANSITIONAL METAL OR AN ALLOY THEREOF COMPRISING PROVIDING AN UNCLAD, THIN-WALLED GRAPHITE CRUCIBLE HAVING A BOTTOM OPENING THEREIN, POSITIONING A FUSIBLE METALLIC MEMBER SUBSTANTIALLY NON-DELETERIOUS TO THE MOLTEN CHARGE METAL AT THE BOTTOM OF SAID CRUCIBLE TO OBTURATE SAID OPENING, POSITIONING A CHARGE OF SAID METAL OR ALLOY TO BE MELTED WITHIN SAID CRUCIBLE ABOVE SAID MEMBER AND RAPIDLY HEATING SAID CHARGE BY ELECTRICAL INDUCTION TO A TEMPERATURE ABOVE ITS MELTING TEOPERATURE WITHOUT SUBSTANTIALLY MELTING SAID MEMBER TO THEREBY PROVIDE A POOL OF MOLTEN METAL FLOWING ONTO THE MEMBER AND THEREBY MELT A POUR HOLE THROUGH THE MEMBER THROUGH WHICH THE MOLTEN CHARGE DISCHARGES FROM THE CRUCIBLE.
Claim 2
Independent Claim
118 words
A METHOD OF MELTING AND POURING AS A MOLTEN CHARGE A TRANSITIONAL METAL OR AN ALLOY THEREOF COMPRISING PROVIDING AN UNCLAD, THIN-WALLED GRAPHITE CRUCIBLE HAVING A BOTTOM OPENING THEREIN, POSITIONING A FUSIBLE METALLIC MEMBER SUBSTANTIALLY NON-DELETERIOUS TO THE MOLTEN CHARGE METAL AT THE BOTTOM OF SAID CRUCIBLE TO OBTURATE SAID OPENING, POSITIONING A CHARGE OF SAID METAL OR ALLOY TO BE MELTED WITHIN SAID CRUCIBLE ABOVE SAID MEMBER AND RAPIDLY HEATING SAID CHARGE BY ELECTRICAL INDUCTION TO A TEMPERATURE ABOVE ITS MELTING TEOPERATURE WITHOUT SUBSTANTIALLY MELTING SAID MEMBER TO THEREBY PROVIDE A POOL OF MOLTEN METAL FLOWING ONTO THE MEMBER AND THEREBY MELT A POUR HOLE THROUGH THE MEMBER THROUGH WHICH THE MOLTEN CHARGE DISCHARGES FROM THE CRUCIBLE.
Claim 3
Dependent Claim
28 words
A method as claimed in claim 1 wherein the graphite crucible has a wall thickness substantially less than the electrical reference depth, Alpha , as herein before defined.
Claim 4
Dependent Claim
20 words
A method as claimed in claim 2 wherein the crucible wall thickness is less than one-fifth the electrical reference depth.
Claim 5
Dependent Claim
20 words
A method as claimed in claim 3 wherein the crucible wall thickness is less than one-tenth the electrical reference depth.
Claim 6
Dependent Claim
40 words
A method as claimed in claim 2 including seating the crucible in a refractory supporting cup the inner wall of which forms a slidable fit with the crucible outer wall and extends to embrace the lower region of the crucible.
Claim 7
Dependent Claim
16 words
A method as claimed in claim 5 in which the supporting cup is a graphite cup.
Claim 8
Dependent Claim
26 words
A method as claimed in claim 5 wherein the inner wall of the crucible is lined with a ceramic material substantially inert to the molten metal.
Claim 9
Dependent Claim
34 words
A method as claimed in claim 7 wherein, in the melting of Ti and Ti alloys, the ceramic material is chosen from tungsten, yttria-stabilised zirconia and yttria- or calcium-stabilised zirconia mixed with titanium hydride.
Claim 10
Dependent Claim
29 words
A method as claimed in claim 7 wherein the crucible lining is provided by plasma spraying a coating of the ceramic material onto the inner wall of the crucible.
Claim 11
Dependent Claim
26 words
A method as claimed in claim 7 wherein the crucible lining is provided by inserting a free-standing liner, fabricated from the ceramic material, into the crucible.
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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |