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US4797165A Expired / Lapsed US ⏱️ 0.0 years remaining

Aluminum-lithium alloys having improved corrosion resistance and method

Assignee: Alcoa Corp
•
Filing: 1984-12-24
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Granted: 1989-01-10
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Expires: 2004-12-24
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Abstract

Abstract An aluminum base alloy wrought product having improved corrosion resistance in addition to combinations of strength and toughness. The product comprises 2.2 to 3.0 wt. % Li, 0.4 to 2.0 wt. % Mg, 0.2 to 1.6 wt. % Cu, 0 to 2.0 wt. % Mn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities and has the ability to develop improved combinations of strength and toughness in response to an aging treatment. Prior to an aging step, the product having imparted thereto a working effect equivalent to stretching so that after an aging step it has improved combinations of strength and toughness.

Inventors

  • 👤 Philip E. Bretz
  • 👤 Ralph R. Sawtell
  • 👤 Warren H. Hunt, Jr.

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 18:53
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/04; C22C; C22C21/00

Claims Analysis

Total Claims: 37
Claim 1
Independent Claim 120 words
An aluminum base alloy wrought product having improved combinations of strength, toughness and corrosion resistance, the product having the ability to develop improved combinations of strength and toughness in response to aging treatment, the product consisting essentially of 2.2 to 3.0 wt. % Li, 0.4 to 2.0 wt. % Mg, 0.2 to 1.6 wt. % Cu, 0 to 2.0 wt. % Mn, 0 to 1.0 wt. % Zr, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product having imparted thereto, prior to an aging step, a working effect equivalent to stretching said product an amount greater than about 3.6% and aging the product to provide improved combinations of strength and toughness.
Claim 2
Dependent Claim 120 words
An aluminum base alloy wrought product having improved combinations of strength, toughness and corrosion resistance, the product having the ability to develop improved combinations of strength and toughness in response to aging treatment, the product consisting essentially of 2.2 to 3.0 wt. % Li, 0.4 to 2.0 wt. % Mg, 0.2 to 1.6 wt. % Cu, 0 to 2.0 wt. % Mn, 0 to 1.0 wt. % Zr, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product having imparted thereto, prior to an aging step, a working effect equivalent to stretching said product an amount greater than about 3.6% and aging the product to provide improved combinations of strength and toughness.
Claim 3
Dependent Claim 20 words
The product in accordance with claim 1 wherein the Cu is in the range of 0.3 to 0.8 wt. %.
Claim 4
Dependent Claim 20 words
The product in accordance with claim 1 wherein the Mg is in the range of 1.0 to 1.4 wt. %.
Claim 5
Dependent Claim 20 words
The product in accordance with claim 1 wherein the Mn is in the range of 0 to 0.5 wt. %.
Claim 6
Dependent Claim 20 words
The product in accordance with claim 1 wherein the Li is in the range of 2.4 to 2.8 wt. %.
Claim 7
Dependent Claim 20 words
The product in accordance with claim 1 wherein the Li is in the range of 2.2 to 2.4 wt. %.
Claim 8
Dependent Claim 53 words
The product in accordance with claim 1 wherein Li is in the range of 2.4 to 3.0 wt. %, Cu is in the range of 0.3 to 0.8 wt. %, Mn is in the range of 0 to 0.5 wt. % and Mg is in the range of 1.0 to 1.4 wt. %.
Claim 9
Dependent Claim 26 words
The product in accordance with claim 1 wherein the working effect is equivalent to stretching said product an amount in the range of 3.6 to 14%.
Claim 10
Dependent Claim 26 words
The product in accordance with claim 1 wherein the working effect is equivalent to stretching said product an amount in the range of 4 to 12%.
Claim 11
Dependent Claim 26 words
The product in accordance with claim 1 wherein the working effect is equivalent to stretching said product an amount in the range of 4 to 8%.
Claim 12
Dependent Claim 21 words
The product in accordance with claim 1 wherein the product is stretched an amount in the range of 3.6 to 14%.
Claim 13
Dependent Claim 21 words
The product in accordance with claim 1 wherein the product is stretched an amount in the range of 4 to 12%.
Claim 14
Dependent Claim 20 words
The product in accordance with claim 1 wherein the product is rolled an amount equivalent to stretching 3.6 to 14%.
Claim 15
Dependent Claim 20 words
The product in accordance with claim 1 wherein the product is forged an amount equivalent to stretching 3.6 to 14%.
Claim 16
Dependent Claim 121 words
An aluminum base alloy wrought product suitable for aging and having the ability to develop improved combinations of strength and fracture toughness in responnse to an aging treatment, the product consisting essentially of 0.5 to 3.0 wt. % Li, 0 to 5.0 wt. % Mg, up to 5.0 wt. % Cu, 0 to 1.0 wt. % Zr, 0 to 2.0 wt. % Mn, 0 to 7.0 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product having imparted thereto, prior to said aging, a working effect equivalent to stretching an amount 4 to 12% at room temperature and aging said product to provide improved combinations of strength and fracture toughness.
Claim 17
Dependent Claim 121 words
An aluminum base alloy wrought product suitable for aging and having the ability to develop improved combinations of strength and fracture toughness in responnse to an aging treatment, the product consisting essentially of 0.5 to 3.0 wt. % Li, 0 to 5.0 wt. % Mg, up to 5.0 wt. % Cu, 0 to 1.0 wt. % Zr, 0 to 2.0 wt. % Mn, 0 to 7.0 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product having imparted thereto, prior to said aging, a working effect equivalent to stretching an amount 4 to 12% at room temperature and aging said product to provide improved combinations of strength and fracture toughness.
Claim 18
Dependent Claim 112 words
An aluminum base alloy wrought product suitable for aging and having the ability to develop improved combinations of strength and fracture toughness in response to an aging treatment, the product consisting essentially of 0.5 to 3.0 wt. % Li, 0 to 5.0 wt. % Mg, up to 5.0 wt. % Cu, 0 to 1.0 wt. % Zr, 0 to 2.0 wt. % Mn, 0 to 7.0 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product, prior to an aging step, stretched 4 to 12% and aging said product to provide improved strength level without a substantial decrease in fracture toughness.
Claim 19
Dependent Claim 112 words
An aluminum base alloy wrought product suitable for aging and having the ability to develop improved combinations of strength and fracture toughness in response to an aging treatment, the product consisting essentially of 0.5 to 3.0 wt. % Li, 0 to 5.0 wt. % Mg, up to 5.0 wt. % Cu, 0 to 1.0 wt. % Zr, 0 to 2.0 wt. % Mn, 0 to 7.0 wt. % Zn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product, prior to an aging step, stretched 4 to 12% and aging said product to provide improved strength level without a substantial decrease in fracture toughness.
Claim 20
Dependent Claim 157 words
Method of making aluminum base alloy products having combinations of improved strength, corrosion resistance and fracture toughness, the method comprising the steps of: (a) providing a lithium-containing aluminum base alloy product consisting essentially of 2.2 to 3.0 wt. % Li, 0.4 to 2.0 wt. % Mg, 0.2 to 1.6 wt. % Cu, 0 to 2.0 wt. % Mn, 0 to 1.0 wt. % Zr, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product having imparted thereto, prior to an aging step, a working effect equivalent to stretching so that after an aging step the product has improved combinations of strength and toughness; and (b) imparting to said product, prior to an aging step, a working effect equivalent to stretching said product an amount greater than about 3.6% at room temperature and aging said product to provide improved combinations of strength and fracture toughness in addition to corrosion resistance.
Claim 21
Dependent Claim 157 words
Method of making aluminum base alloy products having combinations of improved strength, corrosion resistance and fracture toughness, the method comprising the steps of: (a) providing a lithium-containing aluminum base alloy product consisting essentially of 2.2 to 3.0 wt. % Li, 0.4 to 2.0 wt. % Mg, 0.2 to 1.6 wt. % Cu, 0 to 2.0 wt. % Mn, 0 to 1.0 wt. % Zr, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product having imparted thereto, prior to an aging step, a working effect equivalent to stretching so that after an aging step the product has improved combinations of strength and toughness; and (b) imparting to said product, prior to an aging step, a working effect equivalent to stretching said product an amount greater than about 3.6% at room temperature and aging said product to provide improved combinations of strength and fracture toughness in addition to corrosion resistance.
Claim 22
Dependent Claim 20 words
The method in accordance with claim 17 wherein the Cu is in the range of 0.3 to 0.8 wt. %.
Claim 23
Dependent Claim 20 words
The method in accordance with claim 17 wherein the Mg is in the range of 1.0 to 14 wt. %.
Claim 24
Dependent Claim 20 words
The method in accordance with claim 17 wherein the Mn is in the range of 0 to 0.5 wt. %.
Claim 25
Dependent Claim 20 words
The method in accordance with claim 17 wherein the Li is in the range of 2.4 to 2.8 wt. %.
Claim 26
Dependent Claim 22 words
The method in accordance with claim 17 wherein the working effect is equivalent to stretching said body an amount greater than 3.6%.
Claim 27
Dependent Claim 20 words
The method in accordance with claim 17 wherein the working effect is equivalent to stretching said body 4 to 14%.
Claim 28
Dependent Claim 20 words
The method in accordance with claim 17 wherein the working effect is equivalent to stretching said body 4 to 8%.
Claim 29
Dependent Claim 31 words
The method in accordance with claim 17 including homogenizing a body of said alloy at a temperature in the range of 900° to 1050° F. prior to forming into said product.
Claim 30
Dependent Claim 146 words
Method of making aluminum base alloy products having combinations of improved strength and fracture toughness, the method comprising the steps of: (a) providing a lithium-containing aluminum base alloy product consisting essentially of 2.2 to 3.0 wt. % Li, 0.4 to 2.0 wt. % Mg, 0.2 to 1.6 wt. % Cu, 0 to 2.0 wt. % Mn, 0 to 0.2 wt. % Zr, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product having imparted thereto, prior to an aging step, a working effect equivalent to stretching so that after an aging step the product has improved combinations of strength and toughness; and (b) imparting to said product, prior to an aging step, a working effect equivalent to stretching said product an amount greater than 3% and aging said product to provide improved combinations of strength and fracture toughness.
Claim 31
Dependent Claim 146 words
Method of making aluminum base alloy products having combinations of improved strength and fracture toughness, the method comprising the steps of: (a) providing a lithium-containing aluminum base alloy product consisting essentially of 2.2 to 3.0 wt. % Li, 0.4 to 2.0 wt. % Mg, 0.2 to 1.6 wt. % Cu, 0 to 2.0 wt. % Mn, 0 to 0.2 wt. % Zr, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product having imparted thereto, prior to an aging step, a working effect equivalent to stretching so that after an aging step the product has improved combinations of strength and toughness; and (b) imparting to said product, prior to an aging step, a working effect equivalent to stretching said product an amount greater than 3% and aging said product to provide improved combinations of strength and fracture toughness.
Claim 32
Dependent Claim 15 words
The method according to claim 26 wherein said wrought product is stretched 4 to 12%.
Claim 33
Dependent Claim 15 words
The method according to claim 26 wherein said wrought product is stretched 4 to 8%.
Claim 34
Dependent Claim 119 words
An aluminum base alloy wrought product suitable for aging and having improved combinations of strength and fracture toughness in responae to an aging treatment while maintaining high levels of resistance to corrosion, the product consisting essentialIy of 2.2 to 2.8 wt. % Li, 1.0 to 1.4 wt. % Mg, 0.3 to 0.8 wt. % Cu, 0 to 0.2 wt. % Zr, 0 to 0.5 wt. % Mn, 0.5 wt. % max. Fe. 0.5 wt. % max. Si, the balance aluminun and incidental impurities, the product having imparted thereto, prior to an said aging, a working effect equivalent to stretching an amount 4 to 12% at room temperature aging said product to provide improved combinations of strength and fracture toughness.
Claim 35
Dependent Claim 119 words
An aluminum base alloy wrought product suitable for aging and having improved combinations of strength and fracture toughness in responae to an aging treatment while maintaining high levels of resistance to corrosion, the product consisting essentialIy of 2.2 to 2.8 wt. % Li, 1.0 to 1.4 wt. % Mg, 0.3 to 0.8 wt. % Cu, 0 to 0.2 wt. % Zr, 0 to 0.5 wt. % Mn, 0.5 wt. % max. Fe. 0.5 wt. % max. Si, the balance aluminun and incidental impurities, the product having imparted thereto, prior to an said aging, a working effect equivalent to stretching an amount 4 to 12% at room temperature aging said product to provide improved combinations of strength and fracture toughness.
Claim 36
Dependent Claim 120 words
An aluminum base alloy wrought product having improved resistance to exfoliation corrosion and suitable for aging and having the ability to develop improved combinations of strength and fracture toughness in response to an aging treatment while maintaining high levels of resistance to corrosion, the product consisting essentially of 2.2 to 2.8 wt. % Li, 1.0 to 1.4 wt. % Mg, 0.3 to 0.8 wt. % Cu, 0.01 to 0.2 wt. % Zr, 0 to 0.5 wt. % Mn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product, prior to an aging step, stretched 4 to 12% aging said product to provide improved strength level without a substantial decrease in fracture toughness.
Claim 37
Dependent Claim 120 words
An aluminum base alloy wrought product having improved resistance to exfoliation corrosion and suitable for aging and having the ability to develop improved combinations of strength and fracture toughness in response to an aging treatment while maintaining high levels of resistance to corrosion, the product consisting essentially of 2.2 to 2.8 wt. % Li, 1.0 to 1.4 wt. % Mg, 0.3 to 0.8 wt. % Cu, 0.01 to 0.2 wt. % Zr, 0 to 0.5 wt. % Mn, 0.5 wt. % max. Fe, 0.5 wt. % max. Si, the balance aluminum and incidental impurities, the product, prior to an aging step, stretched 4 to 12% aging said product to provide improved strength level without a substantial decrease in fracture toughness.

References Cited (Backward Citations)

US4648913A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-01-10 1992-07-11 1993-01-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-01-10 1996-07-11 1997-01-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-01-10 2000-07-11 2001-01-10 $7700.00 Window Closed / Lapsed

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