US4486244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing superplastic aluminum sheet
Assignee: Reynolds Metals Co
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Filing: 1982-12-17
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Granted: 1984-12-04
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Expires: 2002-12-17
Abstract
Abstract The use of a sequentially applied warm working/cold working procedure in the conventional steps of preparing heat treatable superplastic alloys yields material which demonstrates substantially equiaxed fine grain structure and improved superplastic forming characteristics.
Inventors
- 👤 Bennie R. Ward
- 👤 Suphal P. Agrawal
- 👤 Richard F. Ashton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:03
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/04; C22F1/053; C22F1/057; Y; Y10; Y10S; Y10S420/00; Y10S420/902
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
206 words
In a method for producing superplastic aluminum sheet having a fine (<20 μm) and equiaxed grain structure comprising the steps of: (a) providing an aluminum alloy plate of appropriate composition and desired thickness by hot rolling and stress relieving; (b) solution heat treating the plate at a temperature higher than 860° F. for from about 1/4 to 48 hours; (c) slow cooling the product of step (b) to an average temperature of about 775°; (d) overaging at about 775° F. for from about 2 to 8 hours; (e) slow cooling the product of step (d) to a temperature of between about 450° to about 500° F. and optionally holding this temperature for up to about 4 hours; (f) plastically deforming the product of step (e) from about 40 to about 80%; and (g) rapidly recrystallizing at a temperature of between about 800° and 900° F., the improvement which comprises performing a first portion of the plastic deformation of step (f) by warm rolling at a starting temperature of between about 450° to about 500° F. and performing a second portion of the plastic deformation of step (f) by cold rolling at room temperature, said cold rolling being performed in a direction transverse to said warm rolling.
Claim 2
Dependent Claim
206 words
In a method for producing superplastic aluminum sheet having a fine (<20 μm) and equiaxed grain structure comprising the steps of: (a) providing an aluminum alloy plate of appropriate composition and desired thickness by hot rolling and stress relieving; (b) solution heat treating the plate at a temperature higher than 860° F. for from about 1/4 to 48 hours; (c) slow cooling the product of step (b) to an average temperature of about 775°; (d) overaging at about 775° F. for from about 2 to 8 hours; (e) slow cooling the product of step (d) to a temperature of between about 450° to about 500° F. and optionally holding this temperature for up to about 4 hours; (f) plastically deforming the product of step (e) from about 40 to about 80%; and (g) rapidly recrystallizing at a temperature of between about 800° and 900° F., the improvement which comprises performing a first portion of the plastic deformation of step (f) by warm rolling at a starting temperature of between about 450° to about 500° F. and performing a second portion of the plastic deformation of step (f) by cold rolling at room temperature, said cold rolling being performed in a direction transverse to said warm rolling.
Claim 3
Dependent Claim
35 words
The method of claim 1 wherein the solution heat treating of step (b) is performed at a temperature of between about 860° and about 925° F. and for from about 1/4 to about 24 hours.
Claim 4
Dependent Claim
35 words
The method of claim 1 wherein the overaging of step (d) is performed at a temperature of between about 675° and about 775° F. for a period of from about 2 to about 8 hours.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein the aluminum alloy plate comprises an alloy selected from the group consisting of 7075, 7475, 7050, X7091, X2034, 2219, 2124 and 2014.
Claim 6
Dependent Claim
109 words
In a method of imparting a fine (<20 μm) and equiaxed grain structure to an aluminum alloy having a precipitating constituent, comprising the steps of: (a) dissolving at least some of the precipitating constituent by heating the alloy to solid solution temperature; (b) cooling the alloy to a temperature below the solid solution temperature; (c) plastically straining the alloy; and (d) recrystallizing the alloy, the improvement comprising performing the plastically straining of step (c) by sequentially warm rolling at a starting temperature of between about 450° to about 500° F. and cold rolling at room temperature, said cold rolling being performed in a direction transverse to said warm rolling.
Claim 7
Dependent Claim
109 words
In a method of imparting a fine (<20 μm) and equiaxed grain structure to an aluminum alloy having a precipitating constituent, comprising the steps of: (a) dissolving at least some of the precipitating constituent by heating the alloy to solid solution temperature; (b) cooling the alloy to a temperature below the solid solution temperature; (c) plastically straining the alloy; and (d) recrystallizing the alloy, the improvement comprising performing the plastically straining of step (c) by sequentially warm rolling at a starting temperature of between about 450° to about 500° F. and cold rolling at room temperature, said cold rolling being performed in a direction transverse to said warm rolling.
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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) | 1987-12-04 | 1988-06-04 | 1988-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-04 | 1992-06-04 | 1992-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-04 | 1996-06-04 | 1996-12-04 | $7700.00 | Window Closed / Lapsed |