Structural characterization of aluminium foams by means micro computed tomography

The paper presents the three dimensional analysis of the geometric structure of different aluminium. foams by means of micro tomography at spatial resolutions of 10 mum using a synchrotron radiation based setup, and 100 mum using a tabletop cone beam setup, repectively. The most important methods for the calculation of foam structure parameters by means of 3D image processing methods like feature segmentation and labelling as well as granulometry are described and applied to different closed-cell Al-foams produced by a powder-metallurgical processing route. The analysis steps can be used as a standard procedure to characterize the structure of closed as well as open cell foams or other kind of porous materials like e.g. sponges. As an example, the temporal development of foams during their ageing could be observed by ex-situ determination of the geometric structure parameters. Furthermore, the special properties of monochromatic synchrotron radiation have been used to study quantitatively not only the pore- and cell-wall space at a high resolution, but also the distribution and geometric parameters of the blowing agent TiH2.