Volume reconstruction of SOFC electrode for porosity and tortuosity calculation

The aim of this work is to make tortuosity and porosity measurements by the use of digital volume reconstruction technique. It can be applied on real SOFC electrodes where the sample is sliced by focused ion beam (FIB). The reconstruction is done from the images of each layer of the sample generated by FIB. The geometric parameters, such as porosity and tortuosity, were calculated from a stack of binary images. Porosity was obtained by the ratio between the voxels concerned to pores and the total sample volume. Tortuosity was measured by the use of the Random Walkers algorithm that simulates molecular diffusion conditions without adding a preferential direction bias. The use of 3D reconstruction provided results of porosity calculation more accurate than the traditional classification in two dimensions. The diffusional model described by Random Walkers algorithm represented coherent and well acceptable values for tortuosity.