Claims
- 1. A preform comprising a body having predetermined dimensions and wherein said body comprises a refined grain structure having a cross-section comprising a curvilinear configuration.
- 2. A preform according to claim 1 wherein said grain structure comprises grains having equiaxed shape.
- 3. A preform according to claim 1 wherein said grain structure comprises grains having a grain size of about 3 microns to about 5 microns.
- 4. A preform according to claim 1 wherein said body is formed of a material selected from the group consisting of aluminum, an aluminum alloy, titanium, a titanium alloy and a steel alloy.
- 5. A preform according to claim 1 wherein said body has an elongation of between about 15% and about 35%.
- 6. A preform according to claim 1 wherein said body has an elongation of greater than about 20%.
- 7. A preform formed from a workpiece, the preform prepared by a process comprising the steps of:
moving the workpiece through a die; and concurrently with said moving step, mixing the workpiece with at least one rotating pin to thereby refine the grain structure of the workpiece to thereby form a preform having a refined grain structure having a cross-section comprising a curvilinear configuration.
- 8. A preform prepared by the process according to claim 7 wherein said mixing step comprises:
individually rotating a plurality of pins in corresponding first directions; and collectively rotating the plurality of pins in a second direction.
- 9. A preform prepared by the process according to claim 8 wherein the corresponding first directions are the same as the second direction.
- 10. A preform prepared by the process according to claim 8 wherein the corresponding first directions are opposite to the second direction.
- 11. A preform prepared by the process according to claim 8 wherein said first rotating step comprises individually rotating at least two of the plurality of friction stir pins in opposite directions.
- 12. A preform prepared by the process according to claim 7 further comprising precipitation hardening the workpiece prior to said moving step.
- 13. A preform prepared by the process according to claim 7 further comprising solution heat treating the workpiece at a predetermined temperature schedule after said mixing step.
- 14. A preform prepared by the process according to claim 13 further comprising precipitation heat treating the workpiece by aging at a second predetermined temperature schedule after said solution heat treating step.
- 15. A preform prepared by the process according to claim 7 further comprising heating the workpiece concurrently with said mixing step.
- 16. A preform prepared by the process according to claim 27 further comprising heating at least one of the pin or the die concurrently with said mixing step.
- 17. A preform prepared by the process according to claim 16 wherein said heating step comprises heating the at least one of the pin or the die to a temperature between about 600° F. and about 1000° F.
- 18. A preform prepared by the process according to claim 7 further comprising cooling the die concurrently with said mixing step.
- 19. A preform prepared by the process according to claim 7 wherein the grain structure of the preform comprises grains having equiaxed shape.
- 20. A preform prepared by the process according to claim 7 wherein the grain structure of the preform comprises grains having a grain size of about 3 microns to about 5 microns.
- 21. A preform prepared by the process according to claim 7 wherein the preform comprises a body having an elongation of between about 15% and about 35%.
- 22. A preform prepared by the process according to claim 7 wherein the preform comprises a body having an elongation of greater than about 20%.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 10/145,009, filed May 14, 2002, which is hereby incorporated herein in its entirety by reference.
Divisions (1)
|
Number |
Date |
Country |
Parent |
10145009 |
May 2002 |
US |
Child |
10609951 |
Jun 2003 |
US |