Mechanical Properties of SOFC Anode Support Materials at Operating Conditions

The mechanical properties of solid-oxide fuel cell (SOFC) materials play an important role in manufacturability, durability and lifetime of the devices. Environmental conditions can affect the mechanical properties of materials. It has been shown during testing of quenched samples that point defect concentration and temperature change the elastic modulus and strength of fluorite-structured oxides. In this work, the flexural modulus and strength of pressed Ce0.90Gd0.10O2-x (GDC) bars are investigated under varying oxygen partial pressures at 675℃, under the same conditions SOFCs experience during operation. This is achieved by using a three-point bend fixture on a universal testing machine, with a chamber and furnace to control the environmental conditions. At operating conditions, the strength and modulus of polycrystalline bars do not follow the expected trends of quenched single grains tested by other methods.