Fabrication of sustainable closed-cell aluminium foams using recycled fly ash and eggshell powder

Closed-cell aluminum foams are a novel materials which consists of unique properties such as good mechanical strength combining low mass and high stiffness, high energy and sound absorption, corrosion resistance, and recyclability. In spite of these potential properties, the usage of expensive constituents (stabilizing and foaming agents) and processing methods of making foams hinder its wide spread usage in industrial applications. This work involves the use of cost-effective constituents for processing aluminium foams by stir casting technique. The industrial waste fly ash (Class-F) is used as a source of stabilizing agent and for the first time the viability of waste chicken egg shell is used as a foaming agent to produce sustainable aluminium foams. Ex-situ characterization investigations are carried out on the manufactured foams in accordance with industry standards. It is evident that the produced foams have a fine cell structures with appreciable compressive strength and energy absorption characteristics. The experimental findings indicate that eggshell powder can be used as a cost-effective foaming agent for synthesizing aluminium foams and fly ash as foam stabilizing agent.