Characterization of microcellular materials manufactured using gas diffusion technique

The full three-dimensional microstructure has been successively visualized in situ during deformation. Reconstruction technique has been based on X-ray microtomography. The numerical algorithm has been developed to discretize X-ray reconstructed images in order to create a geometrical model of the microstructure in three-dimensional space. From the set of two-dimensional cross-section bitmaps it constructs a wire-frame model of the surfaces present in the microstructure. The algorithm has been coded in the standard MatLab 6.0 package. The code developed has been tested on closed polycarbonate foam and open aluminium foam. Furthermore, an analytical model for local foaming process has been developed based upon locally selected boundary condition from the two-dimensional global Holls model. This allows comparison of local geometry of the cells as described by the model with a real geometry of cells reconstructed from X-ray microtomographic images. (Jens Nygaard, Ryszard Pyrz)