Investigation of Compressive Properties of Mn/Mg Reinforced Close-Cell Aluminium Metal Foam

Abstract

The work presented in this paper is based on the enhancement of the mechanical properties of the aluminium base closed-cell metal foam through the addition of reinforcing particles in different percentages. Closed-cell aluminium foams with the addition of Mn (1% by weight) and Mg (1.5%, 2%, and 2.5% by weight) are successfully prepared by the melt route method. In this process, Ca (2% by weight) is used as a thickening agent and CaCO₃ (1% by weight) as a foaming agent. The morphology and mechanical behaviour of Al-based metal foam have been examined to investigate the impact of reinforcing elements. It has been concluded that the addition of reinforcing elements initially helped to increase the compressive strength as found in foam-1, but further addition of Mg did not have any beneficial effects. It has been found that the value of compression strength strongly depends on foam density and can be depicted by finding the ratio of yield strength to density. The higher value of the ratio of yield strength to density depicts a better-quality metal form. The results show that the ratio of yield strength to density for foam-0, foam-1, foam-2 and foam-3 in comparison to form-0 is found to be 1.00, 1.35, 1.007 and 0.59. So this can be concluded that foam-1 possesses the highest compressive strength among all forms under investigation. The addition of reinforcing elements increases the length of the plateau which increases the energy absorption. It is found that proper bonding of reinforcing particles helps in improving energy absorption. It is also found that besides the increase in density and variations in pores uniformity, foam-1 is found to be superior among all other foams. By fixing the percentage of Mn by 1 wt%, the best results are obtained by adding 1.5 wt. % Mg in the melt.