Claims
- 1. A process for the preparation of aluminum having high strength and high ductility, comprising:
- A. providing an aluminum base alloy containing from 0.05 to 1.0% iron, from 0.05 to 1.0% silicon, at least one material selected from the group consisting of less than 10.0% magnesium, less than 3.0% manganese, less than 1.0% copper, less than 0.5% chromium, less than 0.5% zinc, less than 0.5% zirconium, less than 0.5% titanium, less than 0.1% boron, others less than 0.5% each, total less than 1.5% balance essentially aluminum;
- B. working said alloy, preferably by rolling or drawing, at a temperature between 450.degree.F and 950.degree.F with a total reduction in excess of 20%;
- C. working said alloy, preferably by rolling or drawing, at a temperature below 450.degree.F with a total reduction in excess of 20%;
- D. holding said alloy at a temperature of from 250 to 650.degree.F for a period of time no greater than defined in the following formula: T (8.95 + log t) = 5,700, wherein T is temperature in degrees Kelvin and t is the maximum time in minutes at temperature T, so that there is no recrystallization throughout the matrix and so ther there is less than 10% loss in tenxile strength; and
- E. repeating step C, thereby resulting in an alloy having a subgrain size of less than 0.001 mm with the subgrain walls being formed of pinned dislocation tangles.
- 2. A process according to claim 1 wherein steps (C) and (D) are repeated.
- 3. A process according to claim 1 wherein step (C) and (D) are repeated a plurality of times.
- 4. A process according to claim 1 wherein working of step (B) is from 550.degree. to 850.degree.F.
- 5. A process according to claim 1 wherein the materials in step (A) are present in the following amounts: silicon from 0.3 to 0.7%, iron from 0.4 to 0.8%, at least one material selected from the group consisting of copper from 0.1 to 0.5%, manganese up to 1.6%, magnesium up to 5.0%, chromium up to 0.2%, zinc up to 0.3%, titanium up to 0.2%, zirconium up to 0.3% and boron up to 0.05%.
- 6. A process according to claim 1 wherein prior to said hot working step (B) the material is homogenized at a temperature above 850.degree.F for at least 4 hours.
- 7. A process according to claim 4 wherein after said hot rolling step the material is rapidly cooled to below 450.degree.F.
- 8. A process according to claim 1 wherein step (B) is rolling at a temperature below 200.degree.F.
Parent Case Info
This is a continuation, of application Ser. No. 140,580, filed May 5, 1971, and now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
3232796 |
Anderson |
Feb 1966 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
140580 |
May 1971 |
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