Fabrication and characterization of hypoeutectic open-cell Al-Si foams using gravity die casting and squeeze casting

Gravity die casting and squeeze casting are the techniques used for the fabrication of hypoeutectic open-cell Al-Si foams which are characterized and studied for their energy absorbing quality in compression tests. The effect of different amounts of sodium chloride (NaCl) (up to 56 vol.%) as a space holder in the casting of aluminum foam on the morphology, density, porosity, compressive and energy absorption properties of aluminum foam was studied. The hypoeutectic Al-Si alloy with NaCl particles as a space holder was used to fabricate the aluminum foam using gravity die casting and squeeze casting. The hypoeutectic open-cell Al-Si foams produced by squeeze casting showed smaller pore size, better pore distribution, higher porosity, good compressive strength and greater energy absorption energy compared to that of gravity die casting. The hypoeutectic open-cell Al-Si foams with 44 vol.% NaCl using squeeze casting showed the best properties among all foams due to its moderate and well-distributed porosity.