Experimental Investigation of Crushing Behavior of Aluminum Matrix Syntactic Foams with Lightweight Aggregates

This study investigates the mechanical properties of aluminum matrix syntactic foams fabricated using perlite, LECA, and pumice aggregates through the vacuum casting method. The process involved packing the aggregates in a mold, applying a multi-step filling procedure with vibration, and using a vacuum pressure of -1 bar and a heating temperature of 560°C to achieve proper infiltration and distribution of the aluminum melt. The study found that the density of syntactic foams varied based on the type of aggregate particles used: perlite (0.24 g/cm³), LECA (0.55 g/cm³), and pumice (1.30 g/cm³). Quasi-static compressive tests revealed that higher density foams exhibited uniform deformation and higher energy absorption efficiency, with porosity values of 63% for perlite, 51% for LECA, and 33% for pumice. The energy absorption efficiency (η) at 50% strain was 85% for perlite, 78% for LECA, and 70% for pumice. The compressive properties and energy absorption capabilities of the foams increased with density, making them suitable for various protective applications.