Effect of Exfoliated Vermiculite as Thickening and Foaming Agent on the Physical Properties of Aluminium Foam

In this paper, exfoliated vermiculite (EV), a siliceous non-metallic particle is used as both thickening and foaming agent to fabricate low-density metal foam via the oxidation reduction method. Aluminium Alloy 5083 is used as base metal. EV particles 0.1 mm size that were dehydrated by preheating were added as thickening agents and EV particles 1 mm size containing 5% moisture are used as foaming agent to produce bubbles. The density of the foam produced is reduced by about 50% when compared to pure Al5083. The macrostructure reveals that 1.5% EV particle addition resulted in uniform foam. Average pore size varied from 0.1 to 2 mm with varying EV %. With an increase in amount of thickening agent percentage, the pore size decreased, but when the thickening agent increased beyond 1.5%, the pores size increased. The density of foam increased with increase in percentage of thickening agent. From the compressive stress–strain curves, at strain rate of 1 mm/min, the plateau stress increased with the density. The energy absorption for the foam is found to be 4 MJ/m3 for 1.5% EV particles. The energy absorption efficiency is 65%.