Abstract
It is very important to understand the strain rate dependence of the plateau stress or the impact energy for the applications to a suitable design of automotive components. Limited data are, however, available for the mechanical response of metallic foams under dynamic loading in comparison with polymer foams. In this study, the mechanical response and absorbed energy of an open-celled SG91A aluminum foam with the low relative density of 0.03–0.065 is evaluated at a dynamic strain rate in ∼ 103 s−1 order in compression by the split Hopkinson pressure bar apparatus. In order to investigate the effect of microstructure in the solid material, solution treatment and aging are performed and then examined at the same dynamic strain rate. As a result, mechanical strength and absorption energy for as-received and heat treated SG91A aluminum foams showed the strain rate dependence. This dependency was clearly decreased by the heat treatment. This mechanical response directly affects the energy absorption: the strain rate dependence of absorption energy is weakened with enhancing the ductility in solid materials by the heat treatment. Therefore, it is possible to control the absorption energy of the metallic foam by the modification of its microstructure, which affects the ductility in the solid material.
