Two-step foaming process combined with hot-rolling in fabrication of an aluminium foam sandwich panel

Abstract The present study addresses a new aluminium foam sandwich (AFS) manufacturing process by simplifying the technological processes and reducing costs by use of a two-step foaming process and hot-rolling. The interface between the coversheet and precursor core was bonded tightly by four passes of hot-rolling at 480 °C to realise simultaneous metallurgical bonding and foaming. The addition of Mg and pre-heated SiC makes the foaming process more stable and increases the apparent viscosity of the melt and decreases the adverse effects of gravity drainage and capillary action. The optimum foaming conditions occurred at a temperature of 720 °C for between 270 s and 390 s.