US5116572A
Expired / Lapsed
US
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Aluminum-lithium alloy
Assignee: Boeing Co
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Filing: 1989-08-28
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Granted: 1992-05-26
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Expires: 2009-08-28
Abstract
Abstract An aluminum-lithium alloy exhibiting good fracture toughness and relatively high strength has a nominal composition of 2.2 percent lithium, 0.6 percent magnesium, 2.5 percent copper, 0.12 percent zirconium with the balance being aluminum and trace elements.
Inventors
- 👤 G. Hari Narayanan
- 👤 R. Eugene Curtis
- 👤 William E. Quist
- 👤 Michael V. Hyatt
- 👤 Sven E. Axter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:08
CPC Classifications
C; C22; C22C; C22C21/00; C22C21/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
62 words
An aluminum-lithium alloy exhibiting good fracture toughness consisting essentially of: ______________________________________
Element Amount (wt. %)
______________________________________
Li 2.0 to 2.4
Mg 0.3 to 0.9
Cu 2.1 to 2.9
Zr 0.08 to 0.15
Fe 0.15 max
Si 0.12 max
Zn 0.25 max
Ti 0.15 max
Cr 0.1 max
Other trace 0.05 max
elements, each
Other trace 0.15 max
elements, total
Al Balance.
______________________________________
Claim 2
Dependent Claim
62 words
An aluminum-lithium alloy exhibiting good fracture toughness consisting essentially of: ______________________________________
Element Amount (wt. %)
______________________________________
Li 2.0 to 2.4
Mg 0.3 to 0.9
Cu 2.1 to 2.9
Zr 0.08 to 0.15
Fe 0.15 max
Si 0.12 max
Zn 0.25 max
Ti 0.15 max
Cr 0.1 max
Other trace 0.05 max
elements, each
Other trace 0.15 max
elements, total
Al Balance.
______________________________________
Claim 3
Dependent Claim
18 words
The alloy of claim 1 wherein said zirconium is present in amounts from about 0.09 to 0.14 percent.
Claim 4
Dependent Claim
20 words
The alloy of claim 1 wherein said magnesium is present in an amount ranging from about 0.4 to 0.8 percent.
Claim 5
Dependent Claim
23 words
The alloy of claim 1 having a nominal composition of 2.2 percent lithium, 0.6 percent magnesium, 2.5 percent copper, and 0.12 percent zirconium.
Claim 6
Dependent Claim
20 words
The alloy of claim 1 wherein said alloy has been aged at a moderately low temperature to near peak strength.
Claim 7
Dependent Claim
23 words
The alloy of claim 1 wherein said alloy has been aged at a temperature in the range of from 250° to 350° F.
Claim 8
Dependent Claim
18 words
The alloy of claim 6 aged at a temperature in the range of from 275° to 325° F.
Claim 9
Dependent Claim
11 words
The alloy of claim 6 aged for 4 to 120 hours.
Claim 10
Dependent Claim
11 words
The alloy of claim 7 aged for 24 to 96 hours.
Claim 11
Dependent Claim
17 words
The alloy of claim 6 aged at a temperature in the range of 250° to 300° F.
Claim 12
Dependent Claim
17 words
The alloy of claim 10 aged at a temperature in the range of 250° to 275° F.
Claim 13
Dependent Claim
15 words
The alloy of claim 11 aged at a temperature on the order of 250° F.
Claim 14
Dependent Claim
12 words
The alloy of claim 10 aged for about 4 to 48 hours.
Claim 15
Dependent Claim
12 words
The alloy of claim 13 aged for about 4 to 24 hours.
Claim 16
Dependent Claim
12 words
The alloy of claim 1 wherein said alloy has been naturally aged.
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) | 1995-05-26 | 1995-11-25 | 1996-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-26 | 1999-11-25 | 2000-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-26 | 2003-11-25 | 2004-05-26 | $7700.00 | Window Closed / Lapsed |