Crushing of aluminum closed cell foams: density and strain rate effects

Quasi-static and high strain rate compression behavior of an Al closed cell foam is determined. The compressive flow stress of the foam is a function of the relative density but exhibits little or no strain rate sensitivity. It is shown that in addition to the flow stress, the energy absorption is also related to the foam density by a similar power law dependence. Metallographic observations of compressively deformed foam confirm the general processes of progressive cell wall collapse, including buckling and tearing modes, and also highlights the role of precursor powder particle boundaries in these events. (CSA)