Claims
- 1. A process for manufacturing an aluminum alloy sheet suitable for high-speed forming, comprising the steps of:
- subjecting, to a homogenization treatment at 480.degree. C. or above, an aluminum alloy ingot containing 4.0 to 10.0 wt. % of Mg, inevitable impurities of Fe and Si whose content is limited to 0.2 wt. % or less, other impurity elements whose content is limited to 0.05 wt. % or less, and the balance of Al;
- subjecting the aluminum alloy ingot, which has undergone the homogenization treatment, to a hot rolling process and a cold rolling process, thereby obtaining a cold rolled sheet; and
- subjecting the cold rolled sheet to an annealing process in which the cold rolled sheet is heated at a temperature of 300.degree. to 450.degree. C. at a heating rate of 200.degree. C./h or less and said cold rolled sheet is maintained for six hours or less at said temperature.
- 2. The process according to claim 1, wherein said aluminum alloy contains 0.1 to 0.5 wt. % of Cu.
- 3. A process for manufacturing an aluminum alloy sheet suitable for high-speed forming, comprising the steps of:
- subjecting, to a homogenization treatment at 480.degree. C. or above, an aluminum alloy ingot containing 4.0 to 10.0 wt. % of Mg, inevitable impurities of Fe and Si whose content is limited to 0.2 wt. % or less, other impurity elements whose content is limited to 0.05 wt. % or less, and the balance of Al;
- subjecting the aluminum alloy ingot, which has undergone the homogenization treatment, to a hot rolling process and a cold rolling process, thereby obtaining a cold rolled sheet; and
- subjecting the cold rolled sheet to an annealling process in which the cold rolled sheet is heated up to a temperature of 480.degree. to 550.degree. C. and maintained at said temperature for 60 seconds or less and then the rolled sheet is cooled down to 100.degree. C. or less at a cooling rate of 10.degree. C./h or more.
- 4. The process according to claim 3, further comprising a step of subjecting said cold rolled sheet to a final cold rolling process at a reduction of 10 to 50%, after said rolled sheet was subjected to an intermediate annealing process at a temperature of 300.degree. to 550.degree. C.
- 5. The process according to claim 3, wherein said aluminum alloy contains 0.1 to 0.5 wt. % of Cu.
- 6. A method for forming an aluminum alloy sheet, comprising the steps of:
- preparing an aluminum alloy sheet made of an aluminum alloy containing from about 4.0 to 10.0% by weight of Mg, inevitable impurities of Fe and Si whose content is limited to about 0.2% by weight or less, and other impurity elements whose content is limited to about 0.05% by weight or less, and the balance being Al;
- wherein an m-value indicating strain rate sensitivity is -0.001 or less, an average ultimate tensile strength value obtained by dividing, by 4, the sum of ultimate tensile strength in a first direction at zero degrees to a rolling direction, double an ultimate tensile strength in a second direction at 45 degrees to the rolling direction, and an ultimate tensile strength in a third direction at 90 degrees to the rolling direction is at least 280 MPa, and a maximum difference in the ultimate tensile direction in said first, second and third directions is at least 5 MPa;
- applying a high-speed deep drawing to said aluminum alloy sheet at an average strain rate of at least 0.01 sec.sup.1.
- 7. The method according to claim 6, wherein the step of preparing includes said aluminum alloy containing from about 0.1 to 0.5% by weight of Cu.
- 8. A method for forming an aluminum alloy sheet, comprising the steps of:
- preparing an aluminum alloy sheet made of an aluminum alloy containing from about 4.0 to 10.0% by weight of Mg, inevitable impurities of Fe and Si whose content is limited to about 0.2% by weight or less, and other impurity elements whose content is limited to about 0.05 % by weight or less, and the balance being Al;
- wherein an m-value indicating strain rate sensitivity is -0.002 or less; and,
- applying a high-speed deep drawing to said aluminum alloy sheet at an average strain rate of at least 0.01 sec.sup.1-.
- 9. The method according to claim 8, wherein the step of preparing includes said aluminum alloy having an x-ray diffraction intensity of a plane of a surface of said aluminum alloy sheet that is 1.5 times an xray diffraction intensity of a plane of a references sample.
- 10. The method according to claim 8, wherein the step of preparing includes said aluminum alloy containing from about 0.1 to 0.5% by weight of Cu.
Priority Claims (3)
Number |
Date |
Country |
Kind |
4-328879 |
Nov 1992 |
JPX |
|
4-328880 |
Nov 1992 |
JPX |
|
4-328881 |
Nov 1992 |
JPX |
|
Parent Case Info
This is a divisional of application Ser. No. 08/152,486 filed on Nov. 12/93, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
5062901 |
Tanaka et al. |
Nov 1991 |
|
5181969 |
Komatsubara et al. |
Jan 1993 |
|
5423925 |
Shoji et al. |
Jun 1995 |
|
Divisions (1)
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Number |
Date |
Country |
Parent |
152486 |
Nov 1993 |
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