Thermo-mechanical properties of (Sr,Y)TiO3 as anode material for solid oxide fuel cells

Low chemical expansion on re-oxidation makes (Sr,Y)TiO3 a potential material for the application as anode for solid oxide fuel cells. Especially for the long term application mechanical stability is an important aspect. Micro-structural and mechanical testing results are presented for the material in the as-sintered reduced state and the state after subsequent oxidation. Crystalline structure and lattice constant was characterised by X-ray diffraction yielding the strain that will be induced by oxidation. Room temperature indentation testing permitted a determination of fracture toughness and Young's modulus, whereas the temperature dependence of the Young's modulus was measured with a resonance method up to 960 degrees C. The strength of the material was measured using ring-on-ring bending test. The fracture toughness as a function of temperature was measured using a combination of pre-indentation induced cracks and ring-on-ring bending test. Furthermore, the elastic modulus and critical strain were determined for porous material. Fracture surface and failure mode were characterised with supplementary scanning electron microscopy. (C) 2012 Elsevier B.V. All rights reserved.