Impedance spectra simulation of yttria-stabilised zirconia/alumina composites

To simulate impedance spectra of yttria-stabilised zirconia/alumina composi tes a digital-image based model has been developed. The computer simulation generates the polycrystalline microstructure of the material by exploiting the Voronoi tessellation technique. Then a 3-D network of cubes is superim posed onto the simulated polycrystalline microstructure and the edges of ea ch cube substituted with discrete RC parallel electrical circuits. The comp osite is, in such a way, converted into a three-dimensional electrical netw ork whose impedance has been calculated at different frequency values. The numerical solution has been performed via an iterative method based on a ma trix non-linear recursion relation. Results of the simulation are presented and compared with experimental data. (C) 1998 Published by Elsevier Scienc e B.V. All rights reserved.