US3791880A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tear resistant sheet and plate and method for producing
Assignee: Alcoa Corp
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Filing: 1972-06-30
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Granted: 1974-02-12
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Expires: 1992-06-30
Abstract
Abstract An aluminum base alloy of the aluminum-zinc-magnesium-copperchromium type with specially controlled composition limits is provided as a sheet or plate type product having the high strength and good resistance to stress corrosion cracking normally associated with this type of alloy but also having exceptional resistance to tearing. Certain prescribed fabrication procedures including thermal treatments are preferably followed in producing the improved product.
Inventors
- 👤 H Hunsicker
- 👤 J Staley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:19
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/04; C22F1/053; C22C; C22C21/00; C22C21/10; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/926; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12063; Y10T428/12493; Y10T428/12639
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
24 words
The method according to claim 1 wherein said product is artificially aged at a temperature of from 200*to 255*F for 10 to 180 hours.
Claim 2
Dependent Claim
63 words
producing said sheet or plate product from said body including: (a) rolling operations which impart to said product strain hardening effects equivalent to a cold rolling reduction of at least 25% in thickness and (b) a thermal exposure to a temperature of at least 940*F sufficient to provide in said product E phase particles having a median size of at least 1400 A.
Claim 3
Dependent Claim
32 words
homogenizing said body at an elevated temperature not exceeding its eutectic temperature of about 890*F for a sufficient period of time to provide a homogeneous distribution of the readily soluble alloy elements,
Claim 4
Dependent Claim
39 words
producing said sheet or plate product from said body and including a thermal exposure to a temperature of at least 940*F sufficient to provide in said product E phase particles having a median size of at least 1400 A.
Claim 5
Dependent Claim
32 words
homogenizing said body at an elevated temperature not exceeding its eutectic temperature of about 890*F for a sufficient period of time to provide a homogeneous distribution of the readily soluble alloy elements,
Claim 6
Dependent Claim
35 words
heating said body to a temperature of at least 940*F for a period of at least 6 hours, said product, when solution heat treated, quenched and artificially aged, exhibiting improved toughness together with high strength.
Claim 7
Dependent Claim
27 words
further heating said body at a rate not exceeding 150*F per hour to a temperature of at least 940*F for a period of at least 6 hours,
Claim 8
Dependent Claim
38 words
The method according to claim 1 wherein said product is artificially aged by heating to a temperature of 200* to 255*F for 2 to 100 hours and thereafter heating to 300* to 335*F for 2 to 12 hours.
Claim 9
Dependent Claim
38 words
The method according to claim 1 wherein said product is artificially aged by heating to a temperature of 200* to 255*F for 2 to 100 hours and thereafter heating to 315* to 350*F for 6 to 24 hours.
Claim 10
Dependent Claim
57 words
hot rolling said body to reduce its thickness and thereafter further rolling said body to produce said product, said rolling operations imparting to said product strain hardening effects equivalent to a cold rolling reduction of at least 25% in thickness. said product, when solution heat treated, quenched and artificially aged, exhibiting improved toughness together with high strength.
Claim 11
Dependent Claim
28 words
The method according to claim 1 wherein, referring to said step (4), the said product is imparted with the equivalent of a cold reduction of at least 45%.
Claim 12
Dependent Claim
31 words
The method according to claim 1 wherein, referring to said step (4), the body is cold rolled to a cold reduction of at least 25% in thickness to produce said product.
Claim 13
Dependent Claim
25 words
The method according to claim 1 wherein, referring to said step (3), the body, after homogenization, is heated to a temperature between 950* and 1000*F.
Claim 14
Dependent Claim
20 words
The method according to claim 1 wherein the product is solution heat treated at a temperature of at least 940*F.
Claim 15
Dependent Claim
21 words
The method according to claim 1 wherein the product is solution heat treated at a temperature of from 950* to 1000*F.
Claim 16
Dependent Claim
17 words
The method according to claim 6 wherein said product ranges in thickness from 0.020 to 0.250 inches.
Claim 17
Dependent Claim
22 words
The method according to claim 1 wherein the further heating of said step 3 is performed subsequent to a hot rolling operation.
Claim 18
Independent Claim
24 words
A method of producing an aluminum base alloy sheet or plate product having high strength and high toughness and resistance to crack propagation comprising:
Claim 19
Dependent Claim
122 words
An improved aluminum base alloy sheet or plate product composed of an alloy consisting essentially of 5.2 to 6.2% Zn, 1.9 to 2.5% Mg, 1.2 to 1.9% Cu, 0.18 to 0.25% Cr, the balance being aluminum and not more than the following amounts of impurities: 0.12% Fe, 0.10% Si, 0.06% Mn and 0.06% Ti, said product having a fine grain structure, a median particle size of 1400 A or larger for the E phase precipitate and low volume fractions of less than 0.45% iron-bearing phase and less than 0.25% silicon-bearing phase, said product, when solution heat treated, quenched and artificially aged, exhibiting a minimum Kc of 100 to 75 ksi Square Root in. at yield strength levels of 60 to 75 ksi.
Claim 20
Dependent Claim
28 words
The improved product according to claim 13 which is clad on at least one side thereof with a layer of an aluminum base alloy which is anodic thereto.
Claim 21
Dependent Claim
105 words
An improved aluminum base alloy sheet or plate product composed of an alloy consisting essentially of 5.2 to 6.2% Zn, 1.9 to 2.5% Mg, 1.2 to 1.9% Cu, 0.18 to 0.25% Cr, the balance being aluminum and not more than the following amounts of impurities: 0.12% Fe, 0.10% Si, 0.06% Mn and 0.06% Ti, said product having a median particle size of 1400 A or larger for the E phase precipitate and low volume fractions of less than 0.45% iron-bearing phase and less than 0.25% silicon-bearing phase, said product, when solution heat treated, quenched and artificially aged, exhibiting high toughness at high yield strength levels.
Claim 22
Independent Claim
24 words
A method of producing an aluminum base alloy sheet or plate product having high strength and high toughness and resistance to crack propagation comprising:
Claim 23
Dependent Claim
28 words
In a method of producing an aluminum base alloy rolled sheet or plate product having high strength and high toughness and resistance to crack propagation the improvement comprising:
Claim 24
Dependent Claim
27 words
The method according to claim 17 wherein in said step (3) said further heating to at least 940*F is at a rate not exceeding 150*F per hour.
Claim 25
Dependent Claim
29 words
The method according to claim 17 wherein rolling procedures are employed which impart to the rolling stock strain hardening effects equivalent to a cold reduction of at least 25%.
Claim 26
Dependent Claim
22 words
The method according to claim 17 wherein the further heating of said step (3) is performed subsequent to a hot rolling operation.
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |