Viewing the early stage of metal foam formation by computed tomography using synchrotron radiation

Foamed aluminium alloy containing 7wt.-% of Si is investigated by µm-resolved X-ray computed tomography (CT) using synchrotron radiation. The foam is fabricated employing a Powder metallurgical route. The evolution of foam microstructure is characterized by studying a series of samples representing different stages of foam expansion obtained by interrupting the foaming process for each sample at different foaming times. The computer tomographic reconstruction provides a 3D image of the pore structure as well as the spatial distribution of the blowing agent and of the pores at different foaming stages.