Mechanical Properties of Al–Si–Mg Foams with Different SiC Contents and Densities

A356/SiCP composites were prepared by stir-casting and were foamed immediately using titanium hydride. The compression properties (compressive strength, plateau stress, and absorbed energy) of foams increase with the increase in relative density (RD) irrespective of the SiC content. While an increasing SiC content improves foam properties, the nature of the increase depends on RD. At higher RD, the properties even out up on normalising with respective composite strength. At lower RD, cell wall ruptures, and cracks in lower SiC foams deteriorating their properties. This is observed in Ashby-Gibson model data where, below 0.2 RD, normalised plateau strength is lower than the predictions. The experimental data across the RD and SiC contents can be approximated by a simple power-law relationship.