Effect of Exfoliated Vermiculite as Thickening and Foaming Agent on the Physical Properties of Aluminium Foam V. V. K. Lakshmi, V. Arun Vikram,K. V. Subbaiah,K. Suresh and B. Surendra Babu Abstract 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/m 3 for 1.5% EV particles. The energy absorption efficiency is 65%. Keywords Metal foam · Composite · Vermiculite · Aluminium 1 Introduction Aluminium closed-cell foams due to lightweight find applications in automobile, shipping, aviation, packaging and military equipment where load bearing and heat insulation are of prime concern. Metal foams possess low strength-to-weight ratio stiffness, low densities and good impact energy absorption in comparison to solid V. V. K. Lakshmi (B ) · V. Arun Vikram · K. Suresh · B. Surendra Babu Department of Mechanical Engineering, GITAM Institute of Technology, Vizag, Andhra Pradesh, India e-mail: Lakshmi.vennela@gmail.com K. V. Subbaiah Department of Mechanical Engineering, AU College of Engineering (A), Vizag, Andhra Pradesh, India © Springer Nature Singapore Pte Ltd. 2020 H. K. Voruganti et al. (eds.), Advances in Applied Mechanical Engineering, Lecture Notes in Mechanical Engineering, https://doi.org/10.1007/978-981-15-1201-8_91 853