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US4735774A
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Aluminum-lithium alloy (4)
Assignee: Boeing Co
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Filing: 1983-12-30
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Granted: 1988-04-05
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Expires: 2003-12-30
Abstract
Abstract An aluminum-lithium alloy exhibiting good fracture toughness and relatively high strength has a nominal composition of 2.5 percent lithium, 1.0 percent magnesium, 1.6 percent copper, 0.12 percent zirconium with the balance being aluminum and trace elements.
Inventors
- 👤 G. Hari Narayanan
- 👤 William E. Quist
- 👤 R. Eugene Curtis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:47
CPC Classifications
C; C22; C22C; C22C21/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
47 words
An aluminum-lithium ingot metallurgy alloy exhibiting good fracture toughness consisting essentially of ______________________________________
Element Amount (wt. %)
______________________________________
Li 2.3 to 2.7
Mg 0.8 to 1.2
Cu 1.3 to 1.9
Zr 0.15 max
Fe 0.15 max
Si 0.12 max
Other trace 0.25 max
elements
Al Balance.
______________________________________
Claim 2
Dependent Claim
47 words
An aluminum-lithium ingot metallurgy alloy exhibiting good fracture toughness consisting essentially of ______________________________________
Element Amount (wt. %)
______________________________________
Li 2.3 to 2.7
Mg 0.8 to 1.2
Cu 1.3 to 1.9
Zr 0.15 max
Fe 0.15 max
Si 0.12 max
Other trace 0.25 max
elements
Al Balance.
______________________________________
Claim 3
Dependent Claim
17 words
The alloy of claim 1 wherein said zirconium is present in amounts up to about 0.10 percent.
Claim 4
Dependent Claim
20 words
The alloy of claim 1 having a nominal composition of 2.5 percent lithium, 1.0 percent magnesium, and 1.6 percent copper.
Claim 5
Dependent Claim
21 words
The alloy of claim 1 wherein said alloy has been aged at a relatively low temperature for a relatively long time.
Claim 6
Dependent Claim
24 words
The alloy of claim 1 wherein said alloy has been aged at a temperature in the range of from 200° F. to 300° F.
Claim 7
Dependent Claim
19 words
The alloy of claim 5 wherein said alloy has been aged for a period of at least one hour.
Claim 8
Dependent Claim
19 words
The alloy of claim 1 wherein said alloy has been aged at a temperature of less than 275° F.
Claim 9
Dependent Claim
16 words
The alloy of claim 7, wherein said alloy has been aged for at least two hours.
Claim 10
Dependent Claim
19 words
The alloy of claim 1 wherein said alloy has been aged at a temperature of less than 250° F.
Claim 11
Dependent Claim
16 words
The alloy of claim 9 wherein said alloy has been aged for at least four hours.
References Cited (Backward Citations)
US2381219A
Cited
GB787665A
Cited
US3346370A
Cited
GB1387586A
Cited
GB2115836A
Cited
GB2121822A
Cited
GB2137227A
Cited
FR2577584A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-05 | 1991-10-05 | 1992-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-05 | 1995-10-05 | 1996-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-05 | 1999-10-05 | 2000-04-05 | $7700.00 | Window Closed / Lapsed |