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US4569703A
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Aircraft stringer material
Assignee: Sumitomo Light Metal Industries Ltd
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Filing: 1983-06-01
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Granted: 1986-02-11
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Expires: 2003-06-01
Abstract
Abstract An aircraft stringer material having high strength, small grain size, good resistance to stress corrosion cracking and a very high degree of workability is produced from an aluminum base alloy consisting essentially of 5.1 to 8.1 wt. % Zn, 1.8 to 3.4 wt. % Mg, 1.2 to 2.6 wt. % Cu, up to 0.20 wt. % Ti and at least one of 0.18 to 0.35 wt. % Cr and 0.05 to 0.25 wt. % Zr, the balance being aluminum and impurities, by a production method characterized by a special annealing step including rapid heating to a temperature of 320 DEG to 500 DEG C. at a heating rate exceeding 11 DEG C./min. Further, a corrosion-resistant stringer material is produced in a manner very similar to the above production method, using the above aluminum alloy as a core and AA7072 alloy as cladding.
Inventors
- 👤 Yoshio Baba
- 👤 Teruo Uno
- 👤 Hideo Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:47
CPC Classifications
B; B64; B64C; B64C1/00; B64C1/06; B64C1/064; C; C22; C22F; C22F1/00; C22F1/04; C22F1/053; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12736; Y10T428/12764
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
164 words
An aircraft stringer material which has been subjected to stepped cold working and then solution heat treatment, said aircraft stringer material consisting of a recrystallized aluminum alloy consisting essentially of 5.1 to 8.1 wt. % zinc, 1.8 to 3.4 wt. % magnesium, 1.2 to 2.6 wt. % copper, at least one of (a) 0.18 to 0.35 wt. % chromium or (b) 0.05 to 0.25 wt. % zirconium, up to 0.20 wt. % titanium, up to 0.05 wt. % iron, up to 0.40 wt. % silicon, up to 0.70 wt. % manganese, and the balance being aluminum and incidental impurities, wherein said impurities do not include any of the components named above, said aircraft stringer material having a grain size not exceeding 100 μm over the entire length thereof and having a first portion thereof which has been cold worked to a cold reduction of 30% or less and a second portion thereof which has been cold worked to a cold reduction greater than 30%.
Claim 2
Dependent Claim
164 words
An aircraft stringer material which has been subjected to stepped cold working and then solution heat treatment, said aircraft stringer material consisting of a recrystallized aluminum alloy consisting essentially of 5.1 to 8.1 wt. % zinc, 1.8 to 3.4 wt. % magnesium, 1.2 to 2.6 wt. % copper, at least one of (a) 0.18 to 0.35 wt. % chromium or (b) 0.05 to 0.25 wt. % zirconium, up to 0.20 wt. % titanium, up to 0.05 wt. % iron, up to 0.40 wt. % silicon, up to 0.70 wt. % manganese, and the balance being aluminum and incidental impurities, wherein said impurities do not include any of the components named above, said aircraft stringer material having a grain size not exceeding 100 μm over the entire length thereof and having a first portion thereof which has been cold worked to a cold reduction of 30% or less and a second portion thereof which has been cold worked to a cold reduction greater than 30%.
Claim 3
Dependent Claim
41 words
An aircraft stringer material as claimed in claim 1, wherein said material has been subjected to said stepped cold working such that said material includes a third portion thereof which has been cold worked to at least a 90% cold reduction.
Claim 4
Dependent Claim
29 words
An aircraft stringer material as claimed in claim 2, wherein said first portion has approximately a 0% cold reduction and said third portion has approximately a 90% cold reduction.
Claim 5
Dependent Claim
151 words
An aircraft stringer material which has been subjected to stepped cold working and then solution heat treatment, said aircraft stringer material consisting of a recrystallized aluminum alloy consisting essentially of 5.1 to 8.1 wt. % zinc, 1.8 to 3.4 wt. % magnesium, 1.2 to 2.6 wt. % copper, 0.18 to 0.35 wt. % chromium, up to 0.20 wt. % titanium, up to 0.50 wt. % iron, up to 0.40 wt. % silicon, up to 0.70 wt. % manganese, and the balance being aluminum and incidental impurities, wherein said impurities do not include any of the components named above, said aircraft stringer material having a grain size not exceeding 100 μm over the entire length thereof and having a first portion thereof which has been cold worked to a cold reduction of 30% or less and a second portion thereof which has been cold worked to a cold reduction greater than 30%.
Claim 6
Dependent Claim
151 words
An aircraft stringer material which has been subjected to stepped cold working and then solution heat treatment, said aircraft stringer material consisting of a recrystallized aluminum alloy consisting essentially of 5.1 to 8.1 wt. % zinc, 1.8 to 3.4 wt. % magnesium, 1.2 to 2.6 wt. % copper, 0.18 to 0.35 wt. % chromium, up to 0.20 wt. % titanium, up to 0.50 wt. % iron, up to 0.40 wt. % silicon, up to 0.70 wt. % manganese, and the balance being aluminum and incidental impurities, wherein said impurities do not include any of the components named above, said aircraft stringer material having a grain size not exceeding 100 μm over the entire length thereof and having a first portion thereof which has been cold worked to a cold reduction of 30% or less and a second portion thereof which has been cold worked to a cold reduction greater than 30%.
Claim 7
Dependent Claim
41 words
An aircraft stringer material as claimed in claim 4, wherein said material has been subjected to said stepped cold working such that said material includes a third portion thereof which has been cold worked to at least a 90% cold reduction.
Claim 8
Dependent Claim
29 words
An aircraft stringer material as claimed in claim 5, wherein said first portion has approximately a 0% cold reduction and said third portion has approximately a 90% cold reduction.
Claim 9
Dependent Claim
185 words
An aircraft stringer material which has been subjected to stepped cold working and then solution heat treatment, said aircraft stringer material comprising an aluminum alloy core and a corrosion-resistant cladding of AA7072 alloy bonded to at least one side of said core, said core consisting of a recrystallized, aluminum alloy consisting essentially of 5.1 to 8.1 wt. % zinc, 1.8 to 3.4 wt. % magnesium, 1.2 to 2.6 wt. % copper, at least one of 0.18 to 0.35 wt. % chromium or 0.05 to 0.25 wt. % zirconium, up to 0.20 wt. % titanium, up to 0.50 wt. % iron, up to 0.40 wt. % silicon, up to 0.70 wt. % manganese, and the balance being aluminum and incidental impurities, wherein said impurities do not include any of the components named above, said aluminum alloy core having a grain size not exceeding 100 μm over the entire length thereof and having a first portion thereof which has been cold worked to a cold reduction of 30% or less and a second portion thereof which has been cold worked to a cold reduction greater than 30%.
Claim 10
Dependent Claim
185 words
An aircraft stringer material which has been subjected to stepped cold working and then solution heat treatment, said aircraft stringer material comprising an aluminum alloy core and a corrosion-resistant cladding of AA7072 alloy bonded to at least one side of said core, said core consisting of a recrystallized, aluminum alloy consisting essentially of 5.1 to 8.1 wt. % zinc, 1.8 to 3.4 wt. % magnesium, 1.2 to 2.6 wt. % copper, at least one of 0.18 to 0.35 wt. % chromium or 0.05 to 0.25 wt. % zirconium, up to 0.20 wt. % titanium, up to 0.50 wt. % iron, up to 0.40 wt. % silicon, up to 0.70 wt. % manganese, and the balance being aluminum and incidental impurities, wherein said impurities do not include any of the components named above, said aluminum alloy core having a grain size not exceeding 100 μm over the entire length thereof and having a first portion thereof which has been cold worked to a cold reduction of 30% or less and a second portion thereof which has been cold worked to a cold reduction greater than 30%.
Claim 11
Dependent Claim
41 words
An aircraft stringer material as claimed in claim 7, wherein said material has been subjected to said stepped cold working such that said material includes a third portion thereof which has been cold worked to at least a 90% cold reduction.
Claim 12
Dependent Claim
29 words
An aircraft stringer material as claimed in claim 8, wherein said first portion has approximately a 0% cold reduction and said third portion has approximately a 90% cold reduction.
Claim 13
Dependent Claim
174 words
An aircraft stringer material which has been subjected to stepped cold working and then solution heat treatment, said aircraft stringer material comprising an aluminum alloy core and a corrosion-resistant cladding of AA7072 alloy bonded to at least one side of said core, said core consisting of a recrystallized aluminum alloy consisting essentially of 5.1 to 8.1 wt. % zinc, 1.8 to 3.4 wt. % magnesium, 1.2 to 2.6 wt. % copper, 0.18 to 0.35 wt. % chromium, up to 0.20 wt. % titanium, up to 0.50 wt. % iron, up to 0.40 wt. % silicon, up to 0.70 wt. % manganese, and the balance being aluminum and incidental impurities, wherein said impurities do not include any of the components named above, said aluminum alloy core having a grain size not exceeding 100 μm over the entire length thereof and having a first portion thereof which has been cold worked to a cold reduction of 30% or less and a second portion thereof which has been cold worked to a cold reduction greater than 30%.
Claim 14
Dependent Claim
174 words
An aircraft stringer material which has been subjected to stepped cold working and then solution heat treatment, said aircraft stringer material comprising an aluminum alloy core and a corrosion-resistant cladding of AA7072 alloy bonded to at least one side of said core, said core consisting of a recrystallized aluminum alloy consisting essentially of 5.1 to 8.1 wt. % zinc, 1.8 to 3.4 wt. % magnesium, 1.2 to 2.6 wt. % copper, 0.18 to 0.35 wt. % chromium, up to 0.20 wt. % titanium, up to 0.50 wt. % iron, up to 0.40 wt. % silicon, up to 0.70 wt. % manganese, and the balance being aluminum and incidental impurities, wherein said impurities do not include any of the components named above, said aluminum alloy core having a grain size not exceeding 100 μm over the entire length thereof and having a first portion thereof which has been cold worked to a cold reduction of 30% or less and a second portion thereof which has been cold worked to a cold reduction greater than 30%.
Claim 15
Dependent Claim
41 words
An aircraft stringer material as claimed in claim 10, wherein said material has been subjected to said stepped cold working such that said material includes a third portion thereof which has been cold worked to at least a 90% cold reduction.
Claim 16
Dependent Claim
29 words
An aircraft stringer material as claimed in claim 11, wherein said first portion has approximately a 0% cold reduction and said third portion has approximately a 90% cold reduction.
References Cited (Backward Citations)
US4305763A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-10 | 1989-08-12 | 1990-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-10 | 1993-08-12 | 1994-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-10 | 1997-08-12 | 1998-02-11 | $7700.00 | Window Closed / Lapsed |