Hybrid foams and lightweight constructions

Mother nature is a smart builder. The cell structure of bones and honeycombs, for example, is particularly resilient and gets by with extremely little material. The process by which these lightweight structures form is just as suitable for foaming metals, plastics and ceramics.

These foams have specific properties depending on the material they are made of. While plastic foams are light and flexible but cannot withstand high temperatures, metal foams are extremely tough but are heavy and not very flexible. Ceramic foams are quite stiff and can resist even very high temperatures, but are rather difficult to shape.

In the automotive and aerospace industries, it would be more effective and resource-saving to combine the flexibility of plastic with the resilience of metal to create a material with entirely new properties. This is exactly what the Fraunhofer researchers are striving to do by developing hybrid foams. What is special about these materials is that they have the potential to acquire completely new characteristics, while at the same time eliminating the specific weaknesses of each constituent, such as the heavy weight of the metal foam.

The efficiency of the novel materials is to be demonstrated in three test applications: One is to increase the sound insulation in a combustion engine, another is to improve the energy absorption in a crash box, and the third is to manufacture lightweight, high-strength components. A research group comprising the Fraunhofer Institutes for Chemical Technology ICT, Manufacturing Engineering and Applied Materials Research IFAM, Ceramic Technologies and Systems IKTS, Silicate Research ISC and Mechanics of Materials IWM has taken up the challenge of developing the multifunctional hybrid foams.