Young's modulus of some SOFCs materials as a function of temperature

Solid oxide fuel cells (SOFCs) have been under great consideration during this last decade and much effort has been dedicated to model their thermo-mechanical behavior, trying to take into account the different properties of the materials, such as their elasticity. In this paper, we report the elastic behavior of three classical materials used in SOFCs as a function of temperature: Yttria stabilized zirconia (YSZ), La0.8Sr0.21MnO3 (LSM) and Ni-YSZ. Both YSZ and LSM present unusual behaviors. The elastic modulus of YSZ first decreases slowly up to 150 degrees C, then dramatically up to 550 degrees C (certainly due to atomic motion) and finally increases probably because of an order-disorder transition (oxygen vacancies). The state of the art on zirconia was reviewed. For the LSM material, Young's modulus could not be determined below 600 degrees C. Above this temperature, samples with totally closed porosity present a continuously increasing modulus, while the other samples have a quite constant modulus. (c) 2007 Elsevier Ltd. All rights reserved.