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US3900313A
Expired / Lapsed
US
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Process for producing die-casting alloys from aluminum scrap
Assignee: Individual
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Filing: 1973-02-02
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Granted: 1975-08-19
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Expires: 1993-02-02
Abstract
Abstract Process for producing die-casting alloys from aluminum scrap by dissolving silicon in the scrap melt, cooling the melt to precipitate second-phase particles, coarsening the precipitated second-phase particles and separating them from the liquid near the eutectic AlSi temperature.
Inventors
- 👤 Hubert Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:06
CPC Classifications
C; C22; C22B; C22B21/00; C22B21/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
148 words
A METHOD FOR THE CONVERSION OF SCRAN ALUMINUM ALLOY TO DIE-CASTING ALLOYS, THE SCRAP ALLOY CONTAINING AT LEAST 70 WEIGHT PERCENT ALUMINUM AND ONE OR MORE IMPURITIES IN IRON, TITANIUM, CALCIUM, MANGANESE, COPPER, MAGNESIUM, ZINC, NICKEL, CHROMIUM, PHOSPHORUS, COMPRISING THE STEPS OF MELTING SAID SCAP ALUMINUM ALLOY, ADDING AND DISSOLVING IN SAID ALUMINUM ALLOY SUFFICIENT SILICON TO OBTAIN BETWEEN 7.5 TO 20 PERCEBT SILICON IN THE MELT, COOLING THE MELT TO CAUSE FORMATION OF ONE OR MORE SOLID INTERMETALLIC CRYSTALLINE PHASES LOWER IN ALUMINUM CONTENT THAN THE REMAINING LIQUID ALUMINUM ALLOY BUT HIGHER THAN SAID SCRAP ALUMINUM ALLOY IN AT LEAST ONE OF SAID IMPURITIES, FURTHER COOLING THE MELT AT SUCH A RATE AND FOR SUFFICIENT TIME TO CAUSE COARSENING OF SAID CRYSTALLINE PHASES WHILE KEEPING THEM SUSPENDED IN THE LIQUID ALLOY, SEPARATING SAID COARSENED CRYSTALS FROM SAID MELT AND RECOVERING AT LEAST THE REMAINING LIQUID ALUMINUM ALLOY.
Claim 2
Independent Claim
148 words
A METHOD FOR THE CONVERSION OF SCRAN ALUMINUM ALLOY TO DIE-CASTING ALLOYS, THE SCRAP ALLOY CONTAINING AT LEAST 70 WEIGHT PERCENT ALUMINUM AND ONE OR MORE IMPURITIES IN IRON, TITANIUM, CALCIUM, MANGANESE, COPPER, MAGNESIUM, ZINC, NICKEL, CHROMIUM, PHOSPHORUS, COMPRISING THE STEPS OF MELTING SAID SCAP ALUMINUM ALLOY, ADDING AND DISSOLVING IN SAID ALUMINUM ALLOY SUFFICIENT SILICON TO OBTAIN BETWEEN 7.5 TO 20 PERCEBT SILICON IN THE MELT, COOLING THE MELT TO CAUSE FORMATION OF ONE OR MORE SOLID INTERMETALLIC CRYSTALLINE PHASES LOWER IN ALUMINUM CONTENT THAN THE REMAINING LIQUID ALUMINUM ALLOY BUT HIGHER THAN SAID SCRAP ALUMINUM ALLOY IN AT LEAST ONE OF SAID IMPURITIES, FURTHER COOLING THE MELT AT SUCH A RATE AND FOR SUFFICIENT TIME TO CAUSE COARSENING OF SAID CRYSTALLINE PHASES WHILE KEEPING THEM SUSPENDED IN THE LIQUID ALLOY, SEPARATING SAID COARSENED CRYSTALS FROM SAID MELT AND RECOVERING AT LEAST THE REMAINING LIQUID ALUMINUM ALLOY.
Claim 3
Dependent Claim
23 words
The method of claim 1, wherein said one or more intermetallic crystalline phases is separated from said remaining liquid aluminum alloy by centrifugation.
Claim 4
Dependent Claim
23 words
The method of claim 1, wherein said one or more intermetallic crystalline phases is separated from said remaining liquid aluminum alloy by filtration.
Claim 5
Dependent Claim
39 words
A method as defined in claim 1 wherein said cooling step is carried out by reducing the temperature of the melt by approximately 50*C per hour from the temperature at which the silicon dissolved down to at least 590*C.
Claim 6
Dependent Claim
35 words
A method as defined in claim 4 wherein said melt containing up to 20 percent silicon is maintained at the end of the cooling step for at least 30 minutes at a temperature of 585*-620*C.
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) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |