Patent US4077813A successfully refreshed from Google Patents.
US4077813A
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Method of producing complex aluminum alloy parts of high temper, and products thereof
Assignee: National Aeronautics and Space Administration
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Filing: 1976-07-26
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Granted: 1978-03-07
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Expires: 1996-07-26
Abstract
Abstract Fully annealed aluminum sheet is first stretch formed to the complex, doubly compound shape of a previously prepared forming die, e.g., an ejection seat blowout panel of a shuttlecraft. The part is then marked with a series of grid lines for monitoring later elongation. Thereafter it is solution heat treated and refrigerated to retard hardening. While still soft, it is stretched a second time on the same die to induce a modicum of work hardening, after which it is aged to the desired stress corrosion resistant temper, perferrably the T8 level, to provide the desired hardness and stress corrosion resistance.
Inventors
- 👤 with respect to an invention of Fletcher James C. Administrator of the National Aeronautics and Space Administration
- 👤 Irvin J. Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:07
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/04; B; B21; B21D; B21D25/00; B21D25/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
129 words
A process for producing an aluminum alloy part of intricate design and very high temper and stress corrosion resistance comprising the steps of: a. forming said part from annealed aluminum alloy to essentially its final shape and dimensions by one of the standard forming operations, such step incidentally causing some work-hardening of said part; b. making the surface of said part with mutually orthogonal grid lines; c. solution-heat-treating said part to again induce an annealed condition therein; d. cold-working said part while in its annealed condition by repeating said forming operation; e. monitoring elongation of said grid lines during said cold-working step; f. stopping said cold-working step when said part has achieved elongation of approximately 11/2 - 2%; and g. artificially aging the part to achieve a T8 temper.
Claim 2
Dependent Claim
129 words
A process for producing an aluminum alloy part of intricate design and very high temper and stress corrosion resistance comprising the steps of: a. forming said part from annealed aluminum alloy to essentially its final shape and dimensions by one of the standard forming operations, such step incidentally causing some work-hardening of said part; b. making the surface of said part with mutually orthogonal grid lines; c. solution-heat-treating said part to again induce an annealed condition therein; d. cold-working said part while in its annealed condition by repeating said forming operation; e. monitoring elongation of said grid lines during said cold-working step; f. stopping said cold-working step when said part has achieved elongation of approximately 11/2 - 2%; and g. artificially aging the part to achieve a T8 temper.
References Cited (Backward Citations)
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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) | 1981-03-06 | 1981-09-05 | 1982-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-06 | 1985-09-05 | 1986-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-06 | 1989-09-05 | 1990-03-07 | $7700.00 | Window Closed / Lapsed |