Crashworthiness performance of lightweight Composite Metallic Foams at high temperatures

Abstract

Based on their special stochastically distributed pores, Composite Metallic Foams (CMFs) represent a promising alternative to the conventional high-density solid structures. However, due to their high sensitivity to temperature changes, the effect of testing temperature on the compression behaviour of CMFs should not be neglected. In this paper, the compressive response of expanded metal mesh (EMM) reinforced metallic foams, manufactured by powder metallurgical route, were evaluated under impact tests (strain rate 95 s−1) as a function of testing temperature (i.e. 25, 75, 150, 250 and 350 °C). The impact properties of high-strength CMFs including strength properties and energy absorption performances, are measured and compared with those obtained under quasi-static (strain rate 5.77·10-3 s−1) loading conditions. The effect of EMM reinforcements on the CMFs properties and collapse mechanisms at the cell-level were discussed according to the testing temperature. The deformation behaviour of the lightweight CMFs was found to be strongly temperature-dependent, highlighting a brittle-to-ductile transition with increasing testing temperature. Finally, based on the quasi-static experimental results, empirical formulae are proposed to predict the impact properties of newly-developed CMFs, i.e. compression strength and energy absorption.