Foamed metals can be produced by a powder metallurgical method invented and patented by the Fraunhofer-Institute IFAM in Bremen, Germany. The process begins with the mixing of metal powders (elemental metals, alloys, or powder blends) with a foaming agent, after which the blend is compacted to yield a dense, semi finished product. Heat treatment at temperatures near the melting point of the matrix material is the next step. During this process the foaming agent, which is homogeneously distributed within the dense metallic matrix, decomposes. The released gas forces the compacted material to expand, forming a highly porous structure. Prior to foaming, the precursor material can be processed into sheets, rods, profiles, and other shapes by conventional techniques like rolling, swaging, or extrusion in order to improve the flow conditions during foaming in moulds. This technology can be used for making 3D near net shape metal foam components, shaped aluminium foam sandwich panels and foam filled hollow structures. These materials provide an excellent specific stiffness, good energy absorbing capabilities and mechanical / acoustical damping properties. Furthermore, a cost reduction compared to competing materials can often be achieved.