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 °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.

► Reliability of a re-oxidation stable SOFC anode material. ► Microstructural and mechanical aspects. ► Young's modulus, strength, fracture toughness and critical strain. ► Effect of porosity on mechanical properties.