Hybridfoams - A new approach for special applications

Two examples for interpenetration hybrid foams were presented, both based on open cell steel foam as host material which was interpenetrated either with polystyrene foam or with a direct foamed SiC-ceramic. The results of compression tests and non-destructive RFDA (resonance frequency damping analysis) show promising material properties. For the metal-polymer hybrid, an improvement of deformation behavior with a negligible increase in density could be observed. Trough the combination of metal and ceramic foam the density nearly doubles compared to each mono material foam. The strength increases clearly and deformation behavior changes from brittle to ductile. The RFDA shows that Young's modulus of hybrid foam is improved and values are similar to polymer and wooden materials (e.g. EP, PMMA, PVC, MDF) but compared to these organic materials the temperature resistance is higher. Even if mono steel foam with same density reaches comparable values of strength and stiffness, the reinforcement by DSiC is an easy and cheap alternative. And in addition, an improved thermal insulation is to be expected. Furthermore, the RFDA shows an enhanced damping for the metal-ceramic hybrid foams. Consequently it might by a promising material for sandwich cores because it sustains higher shearing loads with additional thermal insulation and good mechanical damping.