Cast bumper system and method of manufacturing same

1. A bumper system comprising:

a bumper beam cast from metal;

said metal cast bumper beam including at least a first portion comprised of a first alloy, a second portion comprised of a second alloy being different than said first alloy, and a third portion comprised of a third alloy being different that said first and second alloys.

2. A bumper system as set forth in claim 1 further including a crash box mechanically connected to said metal cast bumper beam.

3. A bumper system as set forth in claim 1 further including a crash box cast from metal and integrally formed with said metal cast bumper beam.

4. A bumper system as set forth in claim 3 wherein said metal cast crash box is comprised of a first crash box alloy being different than said first, second, and third alloys of said metal cast bumper beam.

5. A bumper system as set forth in claim 4 wherein said metal cast crash box includes a first crash box portion comprised of said first crash box alloy and a second crash box portion comprised of a second crash box alloy being different than said first crash box alloy.

6. The bumper system as set forth in claim 5 wherein said first crash box portion includes a rearward portion of said crash box and said second crash box portion includes a forward portion of said crash box positioned adjacent to and forward of said rearward portion.

7. A bumper system as set forth in claim 1 wherein said first portion includes a central portion of said metal cast bumper beam, and said second portion includes a pair of outer portions of said metal cast bumper beam disposed on opposing sides of said central portion.

8. A bumper system as set forth in claim 7 wherein said third portion includes a plurality of reinforcing ribs of said metal cast bumper beam.

9. A bumper system comprising:

a bumper beam;

a crash box;

said crash box and said bumper beam being integrally cast from metal;

said bumper beam including at least a first bumper beam portion comprised of a first bumper beam alloy; and

said crash box including at least a first crash box portion comprised of a first crash box alloy being different than said first bumper beam alloy.

10. A bumper system as set forth in claim 9 wherein said bumper beam further includes a second bumper beam portion comprised of a second bumper beam alloy being different than said first bumper beam alloy and said first crash box alloy.

11. A bumper system as set forth in claim 10 wherein said crash box further includes a second crash box portion comprised of a second crash box alloy being different than said first bumper beam alloy, said first crash box alloy and said second bumper beam alloy.

12. A bumper system as set forth in claim 11 wherein said first bumper beam portion includes a central portion of said metal cast bumper beam, and said second portion includes a pair of outer portions of said metal cast bumper beam disposed on opposing sides of said central portion.

13. A bumper system as set forth in claim 12 wherein said bumper beam includes a third bumper beam portion comprised of a third bumper beam alloy being different than said first and second bumper beam alloys.

14. A bumper system as set forth in claim 9 wherein said crash box further includes a second crash box portion comprised of a second crash box alloy being different than said first bumper beam alloy and said first crash box alloy.

15. A bumper system as set forth in claim 14 wherein one of said first or second crash box portions includes a plurality of reinforcing ribs of said crash box.

16. A method of manufacturing a bumper system comprising:

metal casting a bumper beam having at least a first portion comprised of a first alloy, a second portion comprised of a second alloy being different than the first alloy, and a third portion comprised of a third alloy being different than the first and second alloys.

17. A method as set forth in claim 16 further including mechanically connecting a crash box to the metal cast bumper beam.

18. A method as set forth in claim 16 further including metal casting a crash box integral to the metal cast bumper beam.

19. A method of manufacturing a bumper system as set forth in claim 18 wherein said metal casting the crash box integral to the metal cast bumper beam includes metal casting a first crash box portion comprised of a first crash box alloy and a second crash box portion comprised of a second crash box alloy that is different than the first crash box alloy.

20. A method of manufacturing a bumper system as set forth in claim 19 wherein the first crash box portion is a rearward portion of the crash box and wherein the second crash box portion is a forward portion of the crash box being positioned adjacent to and forward of the rearward portion.

21. A method as set forth in claim 16 wherein the first portion includes a central portion of the metal cast bumper beam and the second portion includes a pair of outer portions of the metal cast bumper beam disposed on opposing sides of the central portion.

22. A method of manufacturing a bumper system comprising:

metal casting a bumper beam and a crash box integrally with one another, wherein the metal cast bumper includes at least a first bumper beam portion comprised of a first bumper beam alloy and the metal cast crash box includes at least a first crash box portion comprised of a first crash box alloy being different than the first bumper beam alloy.

23. A method of manufacturing a bumper system as set forth in claim 22 wherein the metal cast bumper beam further includes a second bumper beam portion comprised of a second bumper beam alloy being different than the first bumper beam alloy and the first crash box alloy.

24. A method of manufacturing a bumper system as set forth in claim 22 wherein the metal cast crash box further includes a second crash box portion comprised of a second crash box alloy being different than the first bumper beam alloy and the first crash box alloy.