Pfinztal, Germany -- A special process may make it possible to improve the mechanical, thermal and acoustic properties of foams, and will particularly benefit lightweight construction.
According to the Fraunhofer Institute's research group working on this process, "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," a statement on the research continued.
According to the research group, the efficiency of the novel multifunctional hybrid foam materials will 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.
Specific properties of these foams depend on the material: plastics foams are "light and flexible but cannot withstand high temperatures," the researchers say, while metal foams are "extremely tough but are heavy and not very flexible." Ceramic foams have other benefits and drawbacks: they are "quite stiff and can resist even very high temperatures, but are rather difficult to shape," the statement adds.
In automotive and aerospace uses, it would be both more effective and save resources 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. These materials are special in having the potential to acquire new characteristics, while eliminating specific weaknesses of each constituent, such as the heavy weight of the metal foam.
The research group consists of 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).