High strain rate behavior of composite metal foams

The mechanical properties of Composite Metal Foams (CMFs) under low speed loading conditions have been considered in a number of studies. This paper aims to extend the current knowledge by investigating the compressive behavior of CMF under higher loading rates. Hopkinson bar experiment was conducted on samples processed through powder metallurgy and casting techniques. The effect of loading rate, sample geometry and sphere size on the mechanical properties and energy absorption capacity was studied. The obtained results reveal that increasing the loading rate improves the strength of CMF especially at strain levels below 30%. This strengthening due to high strain rate loading is mostly attributed to the strain rate sensitivity of the parent metals and the pressurization of the entrapped air inside the spheres.