Formable light weight composites

1. An article comprising:

a light weight composite having

(i) a first metal foil;

(ii) a second metal foil; and

(iii) an extruded polymeric core layer interposed between the first and second metal foils; wherein the polymeric core layer includes:

a synthetic elastomer having either or both of a tensile modulus at 100% elongation of less than about 3 MPa, a tensile elongation at break greater than about 110%, both measured according to ASTM D638-08 at a nominal strain rate of about 0.1; and from about 3 volume percent to less than about 30 volume percent metal fibers based on the total volume of the polymeric core layer;

wherein

the polymeric core layer has an apparent modulus of rigidity according to ASTM D1043-02 of at least about 200 MPa over a temperature range of about −40° C. to about 50° C.; the metal fibers have a weight average length from about 5 μm to about 25 mm;

and the composite material is stamped and welded to a metal material.

2. The article of claim 1 , wherein the polymeric core layer comprises a thermoplastic polymer including a polyethylene copolymer of one or more α-olefins and optionally one or more additives wherein the polyethylene copolymer includes at least about 80 weight % ethylene polymer and has a peak melting temperature as measured according to ASTM D3418-08 or a glass transition temperature as measured according to ASTM D3418-08 above about 80° C. and below about 250° C.

3. The article of claim 1 , wherein the concentration of pores and voids in the polymeric core layer is from 0 to about 10 volume %, based on the total volume of the polymeric core layer.

4. The article of claim 2 , wherein the thermoplastic polymer has a number average molecular weight greater than about 20,000;

the concentration of any grafted polymer in the polymeric core layer is up to about 10 wt. %, based on the total weight of the polymeric core layer;

the first metal foil includes steel, the part is welded to a steel part and the metal fibers include plain carbon steel fibers; and

the thermoplastic polymer has a crystallinity of about 10% or more.

5. The article of claim 4 , wherein the metal fibers are chopped fibers and have a weight average length of about 5 μm to 8 mm.

6. The article of claim 5 , wherein metal fibers are present in an amount from about 5 volume percent to 20 volume percent, based on the total volume of the polymeric core layer;

and the thickness of one or both of the first and second metal foils is 0.15 mm or more.

7. The article of claim 1 , wherein the first metal foil and the second metal foil each have a first surface facing the polymeric core layer, wherein the polymeric core layer contacts at least 70% of the first surfaces of the first and second metal foils.

8. The article of claim 1 , wherein the composite material includes an edge region sealed by crimping and/or bending the composite material.

9. The article of claim 1 , wherein the composite material includes an edge region sealed by an attached cover.

10. The article of claim 1 , wherein the composite material includes an edge region sealed by welding, soldering or brazing.

11. The article of claim 1 , wherein the composite material includes a spacer entirely interposed between the first and second metal foils.

12. The article of claim 1 , wherein the composite material includes a spacer partially interposed between the first and second metal foils.

13. The article of claim 12 , wherein the spacer includes a first region having a first thickness and interposed between the first and second metal foils and a second region having a second thickness greater than the first thickness, wherein the second regions is located away from the first and second metal foils.

14. The article of claim 8 , wherein the article includes a laser weld joint joining the composite material and the metal material.

15. The article of claim 9 , wherein the article includes a laser weld joint joining the composite material and the metal material.

16. The article of claim 10 , wherein the article includes a laser weld joint joining the composite material and the metal material.

17. The article of claim 11 , wherein the article includes a laser weld joint joining the composite material and the metal material.

18. The article of claim 12 , wherein the article includes a laser weld joint joining the composite material and the metal material.

19. The article of claim 1 , wherein the composite material has a cover over one or more edges.

20. The article of claim 1 , wherein the cover is a coating or a lamination over the one or more edges.