Functionally-graded metallic syntactic foams produced via particle pre-compaction

This paper introduces a novel functionally graded metallic syntactic foam. The investigated foams are manufactured while using infiltration casting where molten A356 aluminum flows into the interstitial voids of packed expanded perlite (EP) particle beds. The partial pre-compaction of particle beds enables the creation of distinct and reproducible density gradients within the syntactic foam. In this study, the samples are produced using four gradually increasing compaction forces and are compared to non-compacted samples. X-ray imaging is used to detect the resulting spatial variation of foam density. In addition, quasi-static compression tests are performed to determine the mechanical foam properties. The results suggest that particle pre-compaction is an efficient tool for tailoring the density and mechanical properties of these novel functionally graded materials.