US4921548A
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US
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Aluminum-lithium alloys and method of making same
Assignee: Alcoa Corp
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Filing: 1988-07-01
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Granted: 1990-05-01
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Expires: 2008-07-01
Abstract
Abstract Disclosed is a method of producing an unrecrystallized wrought aluminum-lithium product having improved levels of strength and fracture toughness. The method comprises the steps of providing a body of a lithium containing aluminum base alloy; heating the body to a hot working temperature and hot working the body to a first product. The product is cold worked to a second wrought product and then reheated while avoiding substantial recrystallization thereof, the reheating adapted to relieve stored energy capable of causing recrystallization during a subsequent heat treating step. The product is then solution heat treated, quenched and aged to provide a substantially unrecrystallized product having improved levels of strength and fracture toughness.
Inventors
- 👤 Chul W. Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:42
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/04; C22F1/053; C22F1/047; C22F1/057
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
128 words
A method of producing an unrecrystallized, thin gauge cold rolled aluminum-lithium sheet product having improved levels of strength and fracture toughness, the method comprising the steps of: (a) providing a body of a lithium containing aluminum base alloy; (b) heating the body to a hot rolling temperature; (c) hot rolling the body to a first intermediate gauge product; (d) cold rolling to a second intermediate sheet product; (e) reheating and hot rolling the second intermediate sheet product to a sheet product while avoiding substantial recrystallization thereof, the hot rolling adapted to relieve stored energy capable of initiating recrystallization during a subsequent heat treating step; (f) solution heat treating, quenching and aging said sheet product to provide a substantially unrecrystallized product having improved levels of strength and fracture toughness.
Claim 2
Independent Claim
128 words
A method of producing an unrecrystallized, thin gauge cold rolled aluminum-lithium sheet product having improved levels of strength and fracture toughness, the method comprising the steps of: (a) providing a body of a lithium containing aluminum base alloy; (b) heating the body to a hot rolling temperature; (c) hot rolling the body to a first intermediate gauge product; (d) cold rolling to a second intermediate sheet product; (e) reheating and hot rolling the second intermediate sheet product to a sheet product while avoiding substantial recrystallization thereof, the hot rolling adapted to relieve stored energy capable of initiating recrystallization during a subsequent heat treating step; (f) solution heat treating, quenching and aging said sheet product to provide a substantially unrecrystallized product having improved levels of strength and fracture toughness.
Claim 3
Dependent Claim
26 words
The method in accordance with claim 1 wherein the reheating and hot rolling step is carried out at a temperature of not more than 920° F.
Claim 4
Dependent Claim
23 words
The method in accordance with claim 1 wherein in step (e) not more than 50% reduction in gauge results from said hot rolling.
Claim 5
Dependent Claim
23 words
The method in accordance with claim 1 wherein in step (e) not more than 30% reduction in gauge results from said hot rolling.
Claim 6
Dependent Claim
25 words
The method in accordance with claim 1 wherein in step (e) not more than 15 to 20% reduction in gauge results from said hot rolling.
Claim 7
Dependent Claim
65 words
The method in accordance with claim 1 wherein said product contains 0.5 to 4.0 wt. % Li, 0 to 5.0 wt. % Mg, up to 5.0 wt. % Cu, 0 to 2.0 wt. % Mn, 0 to 7.0 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, and 0 to 1 wt. % Zr the balance aluminum, incidental elements and impurities.
Claim 8
Dependent Claim
42 words
The method in accordance with claim 1 wherein said product contains 1.0 to 4.0 wt. % Li, 0.5 to 4.0 wt. % Cu, 0 to 3.0 wt. % Mg, 0.03 to 0.15 wt. % Zr and 0 to 1.0 wt. % Mn.
Claim 9
Dependent Claim
41 words
The method in accordance with claim 1 wherein said product contains 2.0 to 3.0 wt. % Li, 0.5 to 4.0 wt. % Cu, 0 to 3.0 wt. % Mg, 0.05 to 0.12 wt. % Zr and 0 to 1.0 Wt.% Mn.
Claim 10
Independent Claim
192 words
A method of producing an unrecrystallized, thin gauge cold rolled aluminum-lithium sheet product having improved levels of strength and fracture toughness, the method comprising the steps of: (a) providing a body containing 0.5 to 4.0 wt. % Li, 0 to 5.0 wt. % Mg, up to 5.0 wt. % Cu, 0 to 2.0 Wt.% Mn, 0 to 7.0 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, and 0 to 1 wt. % Zr the balance aluminum, incidental elements and impurities; (b) heating the body to a hot rolling temperature; (c) hot rolling the body to a first intermediate gauge product; (d) cold rolling to a second intermediate sheet product; (e) reheating to a temperature of not more than 920° F. and hot rolling the second intermediate sheet product to provide a reduction of not more than 30% while avoiding substantial recrystallization thereof, the hot rolling adapted to relieve stored energy capable of initiating recrystallization during a subsequent heat treating step; (f) solution heat treating, quenching and aging said hot rolled intermediate sheet product to provide a substantially unrecrystallized product having improved levels of strength and fracture toughness.
Claim 11
Independent Claim
192 words
A method of producing an unrecrystallized, thin gauge cold rolled aluminum-lithium sheet product having improved levels of strength and fracture toughness, the method comprising the steps of: (a) providing a body containing 0.5 to 4.0 wt. % Li, 0 to 5.0 wt. % Mg, up to 5.0 wt. % Cu, 0 to 2.0 Wt.% Mn, 0 to 7.0 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, and 0 to 1 wt. % Zr the balance aluminum, incidental elements and impurities; (b) heating the body to a hot rolling temperature; (c) hot rolling the body to a first intermediate gauge product; (d) cold rolling to a second intermediate sheet product; (e) reheating to a temperature of not more than 920° F. and hot rolling the second intermediate sheet product to provide a reduction of not more than 30% while avoiding substantial recrystallization thereof, the hot rolling adapted to relieve stored energy capable of initiating recrystallization during a subsequent heat treating step; (f) solution heat treating, quenching and aging said hot rolled intermediate sheet product to provide a substantially unrecrystallized product having improved levels of strength and fracture toughness.
Claim 12
Dependent Claim
133 words
An aluminum base alloy wrought product having improved levels of strength and fracture toughness in response to a reheating and light hot rolling treatment, the product comprised of 0.5 to 4.0 wt. % Li, 0 to 5.0 wt. % Mg, up to 5.0 wt. % Cu, 0 to 2.0 wt. % Mn, 0 to 7.0 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, and 0 to 1 wt. % Zr the balance substantially aluminum incidental elements and impurities, the product having improved levels of strength and fracture toughness resulting from a reheating and light hot rolling treatment at a temperature below recrystallization prior to solution heat treating, the reheating being for a time and temperature effective in relieving stored energy capable of causing recrystallization during solution heat treating.
Claim 13
Dependent Claim
133 words
An aluminum base alloy wrought product having improved levels of strength and fracture toughness in response to a reheating and light hot rolling treatment, the product comprised of 0.5 to 4.0 wt. % Li, 0 to 5.0 wt. % Mg, up to 5.0 wt. % Cu, 0 to 2.0 wt. % Mn, 0 to 7.0 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, and 0 to 1 wt. % Zr the balance substantially aluminum incidental elements and impurities, the product having improved levels of strength and fracture toughness resulting from a reheating and light hot rolling treatment at a temperature below recrystallization prior to solution heat treating, the reheating being for a time and temperature effective in relieving stored energy capable of causing recrystallization during solution heat treating.
Claim 14
Dependent Claim
26 words
The product in accordance with claim 10 wherein the reheating and light hot rolling treatment is performed at a temperature of not more than 920° F.
Claim 15
Dependent Claim
24 words
The product in accordance with claim 10 wherein the light hot rolling treatment results in a reduction of gauge of not more than 50%.
Claim 16
Dependent Claim
26 words
The product in accordance with claim 10 wherein the light hot rolling treatment results in a reduction of gauge of not more than 15 to 20%.
Claim 17
Dependent Claim
31 words
The product in accordance with claim 10 wherein Li is in the range of 1.0 to 4.0 wt. % and Zr is in the range of 0.03 to 0.15 wt. %.
Claim 18
Dependent Claim
19 words
The product in accordance with claim 10 wherein Cu is in the range of 1.0 to 5.0 wt. %.
Claim 19
Dependent Claim
63 words
The product in accordance with claim 10 wherein Li is in the range of 2.0 to 3.0 wt. %, Cu is in the range of 0.5 to 4.0 wt. %, Mg is in the range 0 to 3.0 wt. %, Zr is in the range of 0.03 to 0.2 wt. % and Mn is in the range of 0 to 1.0 wt. %.
Claim 20
Dependent Claim
142 words
An aluminum base alloy wrought product having improved levels of strength and fracture toughness in response to a reheating and light hot rolling treatment, the product comprised of 2.0 to 3.0 wt. % Li, 0 to 3.0 wt. % Mg, 0.5 to 4.0 wt. % Cu, 0 to 1.0 wt. % Mn, 0.03 to 0.2 wt. % Zr, 0.5 Wt.% max. Fe, 0.5 wt. % max. Si, the balance substantially aluminum, incidental elements and impurities, the product having improved levels of strength and fracture toughness resulting from reheating said product to a temperature below recrystallization prior to solution heat treating, the reheating being to a temperature less than 920° F. and for a time effective in relieving stored energy capable of causing recrystallization during solution heat treating and the light hot rolling providing a reduction of not more than 15 to 20%.
Claim 21
Dependent Claim
142 words
An aluminum base alloy wrought product having improved levels of strength and fracture toughness in response to a reheating and light hot rolling treatment, the product comprised of 2.0 to 3.0 wt. % Li, 0 to 3.0 wt. % Mg, 0.5 to 4.0 wt. % Cu, 0 to 1.0 wt. % Mn, 0.03 to 0.2 wt. % Zr, 0.5 Wt.% max. Fe, 0.5 wt. % max. Si, the balance substantially aluminum, incidental elements and impurities, the product having improved levels of strength and fracture toughness resulting from reheating said product to a temperature below recrystallization prior to solution heat treating, the reheating being to a temperature less than 920° F. and for a time effective in relieving stored energy capable of causing recrystallization during solution heat treating and the light hot rolling providing a reduction of not more than 15 to 20%.
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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) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |