Viewing the Early Stage of Metal Foam Formation by Computed Tomography using Synchrotron Radiation

Foamed aluminium alloy containing 7 wt.‐% 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 blowing agent particles. A statistical evaluation allows to determine the size distribution of the blowing agent and of the pores at different foaming stages.