CHARACTERIZATION OF DEFORMATION AND DAMAGE IN POROUS SOFC COMPONENTS VIA SPHERICAL INDENTATION AND SIMULATION.

The aim of this work is to present the methodology to characterize deformation and contact damage initiation and evolution in porous bulk and film components used in solid oxide fuel cells, based on indentation and simulation. Spherical indentation tests at a broad range of loads (50-10000 mN) were carried out on porous bulk and film electrodes with different levels of porosity, and on bilayer system. An axisymmetric model based on the Gurson model used for porous materials was developed to simulate the indentation processes. Elasticity and hardness of each component were reliably determined via both experiments and modelling. Inverse analysis via comparison of experimental indentation response curves and simulation-generated curves shows a very different relation between hardness and yield stress, compared with dense materials. Cracking behaviour was examined and appropriately explained by FEM results. Further insight of the deformation and damage behaviour was also obtained based on microstructural study using FIB-SEM. Overall, the study shows that the model developed in this work is highly applicable for the description the deformation and damage characteristics in porous bulk and film ceramics. [ABSTRACT FROM AUTHOR]