Patent US3847681A successfully refreshed from Google Patents.
US3847681A
Expired / Lapsed
US
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Processes for the fabrication of 7000 series aluminum alloys
Assignee: United States Department of the Army
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Filing: 1973-11-09
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Granted: 1974-11-12
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Expires: 1993-11-09
Abstract
Abstract Improved 7075 aluminum alloy sheet or plate having a very fine grain structure, and fabricated by processes suitable for use with both wrought or as-cast ingot material, the processes including an intermediate thermal mechanical treatment wherein the ingot, for example, is prehomogenized at a relatively high temperature to precipitate out the chromium and then annealed to precipitate zinc, magnesium and copper out of solution as coarse compounds, the prehomogenization and annealing steps rendering the ingot amenable to one or more subsequent deformationrecrystallization steps to provide additional grain structure refinement.
Inventors
- 👤 J Waldman
- 👤 H Sulinski
- 👤 H Markus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:19
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/04; C22F1/053
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
204 words
A COMMERCIALLY FEASIBLE, INTERMEDIATED THERMAL MECHANICAL TREATMENT FOR 7,000 SERIES ALUMINUM ALLOYS FOR IMPROVING DUCTILITY AND FRACTURE TOUGHNESS THEREOF WITHOUT CONCOMITANT REDUCTION IN THEIR STRENGTHS, SAID TREATMENT BEING APPLICABLE TO AS-CAST INGOT ALLOY OR WROUGHT ALLOY, PLATE OR SHEET, SAID TREAT MENT STEPS COMPRISING PREHOMOGENIZING SAID ALLOY AT 860*F. FOR 8 TO 48 HOURS TO DISSOLVE THE INTERDENTRITIC NETWORKS OF ZN-MG- AND CUBEARING COMPOUNDS AND TO PRECIPITATE CR OUT OF SOLUTION, SLOWLY COOLING SAID PREHOMOENIZED ALLOY TO 775*F IN ABOUT 3 H0URS, ANNEALING SAID COOLED PREHOMOGENIZED ALLOY AT 775*F FOR 3 TO 5 HOURS; SLOWLY COOLING SAID ANNEALED ALLOY TO A TEMPERATURE RANGE OF ABOUT 450* TO 500*F AND HOLDING AT SAID TEMPERATURE RANGE FOR 4 HOURS TO PRECIPITATE THE ZN, MG AND CU OUT OF SOLUTION AS COARSE COMPOUNDS TO RENDER THE ALLOY AMENABLE TO PLASTIC DEFORMATION, PLSTICALLY DEFORMING SAID STABILIZED ALLOY AT LEAST 50 PERCENT AT A TEMPERATURE FROM AMBIENT TO 500*F TO GENERATE SUFFICIENT STORED ENERGY THERWITHIN TO ENABLE RECRYSTALLIZATION OF SAID STABILIZED ALLOY INTO A FINE GRANIED STRUCTURE, AND RAPIDLY RECRYSTALLIZING AND HOMOGENIZING SAID DEFORMED ALLOY AT A TEMPERATURE RANGING BETWEEN 860* TO 900*F FOR 24 TO 48 HOURS TO PROVIDE SAID DEFORMED ALLOY WITH A FINE GRAINED RECRYSTALLIZED STRUCTURE.
Claim 2
Dependent Claim
204 words
A COMMERCIALLY FEASIBLE, INTERMEDIATED THERMAL MECHANICAL TREATMENT FOR 7,000 SERIES ALUMINUM ALLOYS FOR IMPROVING DUCTILITY AND FRACTURE TOUGHNESS THEREOF WITHOUT CONCOMITANT REDUCTION IN THEIR STRENGTHS, SAID TREATMENT BEING APPLICABLE TO AS-CAST INGOT ALLOY OR WROUGHT ALLOY, PLATE OR SHEET, SAID TREAT MENT STEPS COMPRISING PREHOMOGENIZING SAID ALLOY AT 860*F. FOR 8 TO 48 HOURS TO DISSOLVE THE INTERDENTRITIC NETWORKS OF ZN-MG- AND CUBEARING COMPOUNDS AND TO PRECIPITATE CR OUT OF SOLUTION, SLOWLY COOLING SAID PREHOMOENIZED ALLOY TO 775*F IN ABOUT 3 H0URS, ANNEALING SAID COOLED PREHOMOGENIZED ALLOY AT 775*F FOR 3 TO 5 HOURS; SLOWLY COOLING SAID ANNEALED ALLOY TO A TEMPERATURE RANGE OF ABOUT 450* TO 500*F AND HOLDING AT SAID TEMPERATURE RANGE FOR 4 HOURS TO PRECIPITATE THE ZN, MG AND CU OUT OF SOLUTION AS COARSE COMPOUNDS TO RENDER THE ALLOY AMENABLE TO PLASTIC DEFORMATION, PLSTICALLY DEFORMING SAID STABILIZED ALLOY AT LEAST 50 PERCENT AT A TEMPERATURE FROM AMBIENT TO 500*F TO GENERATE SUFFICIENT STORED ENERGY THERWITHIN TO ENABLE RECRYSTALLIZATION OF SAID STABILIZED ALLOY INTO A FINE GRANIED STRUCTURE, AND RAPIDLY RECRYSTALLIZING AND HOMOGENIZING SAID DEFORMED ALLOY AT A TEMPERATURE RANGING BETWEEN 860* TO 900*F FOR 24 TO 48 HOURS TO PROVIDE SAID DEFORMED ALLOY WITH A FINE GRAINED RECRYSTALLIZED STRUCTURE.
Claim 3
Dependent Claim
26 words
The method as described in claim 1 further characterized by said recrystallized alloy being further plastically deformed about 40 to 60 percent by conventional mill practice.
Claim 4
Dependent Claim
20 words
The method as described in claim 1 further characterized by said recrystallized alloy being heat treated to a desired temper.
Claim 5
Dependent Claim
25 words
The method as described in claim 2 further characterized by said plastically deformed by conventional mill practice alloy being heat treated to a desired temper.
Claim 6
Dependent Claim
25 words
The method as described in claim 1 further characterized by a plurality of annealing-deformation-recrystallization steps subsequent to said recrystallization step to provide further grain refinement.
Claim 7
Dependent Claim
155 words
An intermediate thermal mechanical treatment for producing 7075 aluminum sheet alloy having improved ductility without concomitant reduction in its strength, said alloy having a reduction in area of 42.1 percent, said treatment comprising the steps of prehomogenizing said alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said prehomogenized alloy to 775*F and soaking thereat for 5 hours, additionally furnace cooling said alloy to 500*F, air cooling said furnace cooled alloy to room temperature, initially rolling said air cooled alloy at room temperature to reduce the thickness thereof, recrystallizing said initially rolled alloy by rapidly heating to 860*F, homogenizing said recrystallized alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said recrystallized and homogenized alloy at 800*F, finally rolling said furnace cooled alloy at 800*F, air cooling said finally rolled alloy at room temperature, and heat treating said air cooled alloy to a T6 temper.
Claim 8
Dependent Claim
155 words
An intermediate thermal mechanical treatment for producing 7075 aluminum sheet alloy having improved ductility without concomitant reduction in its strength, said alloy having a reduction in area of 42.1 percent, said treatment comprising the steps of prehomogenizing said alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said prehomogenized alloy to 775*F and soaking thereat for 5 hours, additionally furnace cooling said alloy to 500*F, air cooling said furnace cooled alloy to room temperature, initially rolling said air cooled alloy at room temperature to reduce the thickness thereof, recrystallizing said initially rolled alloy by rapidly heating to 860*F, homogenizing said recrystallized alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said recrystallized and homogenized alloy at 800*F, finally rolling said furnace cooled alloy at 800*F, air cooling said finally rolled alloy at room temperature, and heat treating said air cooled alloy to a T6 temper.
Claim 9
Dependent Claim
37 words
The method as described in claim 6 wherein said initial rolling step reduces the thickness of the alloy approximately 70 percent and said final rolling step reduces the final cumulative thickness of the alloy approximately 90 percent.
Claim 10
Dependent Claim
146 words
An intermediate thermal mechanical treatment for producing 7075 aluminum sheet alloy having improved ductility without concomitant reduction in its strength, said alloy having a reduction in area of 44.0 percent, said treatment comprising prehomogenizing said alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said prehomogenized alloy to 775*F and soaking thereat for 5 hours, additionally furnace cooling said alloy to 500*F, air cooling said furnace cooled alloy to room temperature, initially rollIng said air cooled alloy at room temperature to reduce the thickness thereof, recrystallizing said initially rolled alloy by rapidly heating to 900*F, homogenizing said recrystallized alloy at 900*F for 1 hour, furnace cooling said recrystallized and homogenized alloy at 800*F, finally rolling said furnace cooled alloy at 800*F, air cooling said finally rolled alloy at room temperature, and heat treating said air cooled alloy to a T6 temper.
Claim 11
Dependent Claim
146 words
An intermediate thermal mechanical treatment for producing 7075 aluminum sheet alloy having improved ductility without concomitant reduction in its strength, said alloy having a reduction in area of 44.0 percent, said treatment comprising prehomogenizing said alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said prehomogenized alloy to 775*F and soaking thereat for 5 hours, additionally furnace cooling said alloy to 500*F, air cooling said furnace cooled alloy to room temperature, initially rollIng said air cooled alloy at room temperature to reduce the thickness thereof, recrystallizing said initially rolled alloy by rapidly heating to 900*F, homogenizing said recrystallized alloy at 900*F for 1 hour, furnace cooling said recrystallized and homogenized alloy at 800*F, finally rolling said furnace cooled alloy at 800*F, air cooling said finally rolled alloy at room temperature, and heat treating said air cooled alloy to a T6 temper.
Claim 12
Dependent Claim
37 words
The method as described in claim 8 wherein said initial rolling step reduces the thickness of the alloy approximately 70 percent and said final rolling step reduces the final cumulative thickness of the alloy approximately 90 percent.
Claim 13
Dependent Claim
144 words
An intermediate thermal mechanical treatment for producing 7075 aluminum sheet alloy having improved ductility without concomitant reduction in its strength, said alloy having reduction in area of 42.6 percent, said treatment comprising the steps of prehomogenizing said alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said prehomogenized alloy to 775*F and soaking thereat for 5 hours, additionally furnace cooling said alloy to 500*F, initially rolling said furnace cooled alloy at 500*F to reduce the thickness thereof, recrystallizing said initially rolled alloy by rapid heating to 860*F, homogenizing said recrystallized alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said recrystallized and homogenized alloy to 800*F, finally rolling said furnace cooled alloy at 800*F, air cooling said finally rolled alloy at room temperature, and heat treating said air cooled alloy to a T6 temper.
Claim 14
Dependent Claim
144 words
An intermediate thermal mechanical treatment for producing 7075 aluminum sheet alloy having improved ductility without concomitant reduction in its strength, said alloy having reduction in area of 42.6 percent, said treatment comprising the steps of prehomogenizing said alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said prehomogenized alloy to 775*F and soaking thereat for 5 hours, additionally furnace cooling said alloy to 500*F, initially rolling said furnace cooled alloy at 500*F to reduce the thickness thereof, recrystallizing said initially rolled alloy by rapid heating to 860*F, homogenizing said recrystallized alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said recrystallized and homogenized alloy to 800*F, finally rolling said furnace cooled alloy at 800*F, air cooling said finally rolled alloy at room temperature, and heat treating said air cooled alloy to a T6 temper.
Claim 15
Dependent Claim
37 words
The method as described in claim 10 wherein said initial rolling step reduces the thickness of the alloy approximately 64 percent and said final rolling step reduces the final cumulative thickness of the alloy approximately 90 percent.
Claim 16
Dependent Claim
138 words
An intermediate thermal mechanical treatment for producing 7075 aluminum sheet alloy having improved ductility without concomitant reduction in its strength, said alloy having reduction in area of 44.4 percent, said treatment comprising the steps of prehomogenizing said alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said prehomogenized alloy to 775*F and soaking thereat for 5 hours, additionally furnace cooling said alloy to 500*F, initially rolling said furnace cooled alloy at 500*F to reduce the thickness thereof, recrystallizing said initially rolled alloy by rapid heating to 900*F, homogenizing said recrystallized alloy at 900*F for 1 hour, furnace cooling said recrystallized and homogenized alloy to 800*F, finally rolling said furnace cooled alloy at 800*F, air cooling said finally rolled alloy at room temperature, and heat treating said air cooled alloy to a T6 temper.
Claim 17
Dependent Claim
138 words
An intermediate thermal mechanical treatment for producing 7075 aluminum sheet alloy having improved ductility without concomitant reduction in its strength, said alloy having reduction in area of 44.4 percent, said treatment comprising the steps of prehomogenizing said alloy at 860*F for 7 hours and at 900*F for 17 hours, furnace cooling said prehomogenized alloy to 775*F and soaking thereat for 5 hours, additionally furnace cooling said alloy to 500*F, initially rolling said furnace cooled alloy at 500*F to reduce the thickness thereof, recrystallizing said initially rolled alloy by rapid heating to 900*F, homogenizing said recrystallized alloy at 900*F for 1 hour, furnace cooling said recrystallized and homogenized alloy to 800*F, finally rolling said furnace cooled alloy at 800*F, air cooling said finally rolled alloy at room temperature, and heat treating said air cooled alloy to a T6 temper.
Claim 18
Dependent Claim
37 words
The method as described in claim 12 wherein said initial rolling step reduces the thickness of the alloy approximately 64 percent and said final rolling step reduces the final cumulative thickness of the alloy approximately 90 percent.
Claim 19
Dependent Claim
30 words
An intermediate thermal mechanical treatment for producing 7075 aluminum alloy plate having improved ductility and fracture toughness without concomitant reduction in its strength, said alloy having the following mechanical properties:
Claim 20
Dependent Claim
30 words
An intermediate thermal mechanical treatment for producing 7075 aluminum alloy plate having improved ductility and fracture toughness without concomitant reduction in its strength, said alloy having the following mechanical properties:
Claim 21
Dependent Claim
20 words
The method as described in claim 14 wherein said rolling step reduces the thickness of the alloy approximately 81 percent.
Claim 22
Dependent Claim
30 words
An intermediate thermal mechanical treatment for producing 7075 aluminum alloy plate having improved ductility and fracture toughness without concomitant reduction in its strength, said alloy having the following mechanical properties:
Claim 23
Dependent Claim
30 words
An intermediate thermal mechanical treatment for producing 7075 aluminum alloy plate having improved ductility and fracture toughness without concomitant reduction in its strength, said alloy having the following mechanical properties:
Claim 24
Dependent Claim
43 words
The method as described in claim 16 wherein said initial rolling step reduces the thickness of the alloy approximately 81 percent and said final rolling step reduces the thickness of the alloy an additional 40 percent, a total reduction of about 89 percent.
References Cited (Backward Citations)
US3706606A
Cited
US3743549A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |