Metal foam

A metal foam is a porous structure consisting of a solid metal (frequently aluminium) with gas-filled pores which can be sealed (closed-cell foam) or interconnected (open-cell foam). Porosity ranges from 5 to 25%. Metal foams retain some physical properties of their base material, for example foam made from non-flammable metal remains non-flammable.

In high speed impact and ballistics, Composite Metal Foam (CMF) is made from a combination of homogeneous hollow metal spheres with a metallic matrix surrounding the spheres. Its resistance to .50 calibre rounds found that CMF could stop such rounds at less than half the weight of rolled homogeneous armor.

Other potential applications include:


 * nuclear waste (shielding X-rays, gamma rays and neutron radiation) transfer
 * thermal insulation for space vehicle atmospheric re-entry, with many times more the resistance to fire and heat as the plain metals
 * absorbs/mitigates shocks, sounds, and vibrations
 * can withstand over 1,000,000 high load cycles, outperforming traditional solid metals in each case