On the compressive behaviour of high porosity expanded Perlite-Metal Syntactic Foam (P-MSF)

A high porosity Perlite-Metal Syntactic Foam (P-MSF) is produced by the pre-compaction of a packed bed of expanded perlite particles prior to counter gravity infiltration with molten aluminium. The density of the resulting high porosity (>70 vol%) syntactic foam is in the range of 0.72-0.98 g/cm3, depending on the particle pre-compaction pressure and the number of compaction steps. Compressive testing is carried out following the ISO 13314 standard to characterise the mechanical properties of this novel material. Furthermore, micro-computed tomography scans are performed in order to investigate its meso-structure. The geometrical analysis revealed that the densification procedure generates a porosity gradient in the direction of the compressive force. This gradient is found to affect the deformation mechanism and thus the mechanical properties of high porosity P-MSF.