A MACROSCOPIC MODEL OF THE THERMO-CHEMO-MECHANICAL BEHAVIOUR OF MIXED IONIC AND ELECTRONIC CONDUCTORS

Olivier Valentin (1) , Camille Gazeau (1) , Eric Blond (1) , Pierre-Marie Geffroy (2) , Nicolas Richet (3)

1 F2ME
2 Axe 1 : procédés céramiques
3 CRCD - Centre de Recherche Claude Delorme [Jouy-en-Josas]

This paper suggests a macroscopic model describing the thermo-chemo-mechanical behaviour of ceramic dense membrane for oxygen separation application. This work takes in account to oxygen permeation and strain induced by stoichiometry variation with working conditions. This model, developed within the traditional framework of phenomenological approach, is based on the assumption of strain partitions and requires only three state variables: oxygen activity, temperature and total strain. Oxygen bulk diffusion and surface exchanges are described thanks to the thermodynamic approach developed by Onsager. While many works focused on semi-permeation induced strain, the proposed model also includes the temperature effect on chemical expansion. Strains predicted by the proposed model are validated thanks to experimental test on La0.8Sr0.2Fe0.7Ga0.3O3-δ. Implemented in F.E.A code Abaqus, this model permits studying the design and the process management effects such as chemical shocks on the membrane reliability.

Domaines: Matériaux et structures en mécanique [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]

Olivier Valentin, Camille Gazeau, Eric Blond, Pierre-Marie Geffroy, Nicolas Richet. A MACROSCOPIC MODEL OF THE THERMO-CHEMO-MECHANICAL BEHAVIOUR OF MIXED IONIC AND ELECTRONIC CONDUCTORS. ASME 2012 11th Biennial Conference on Engineering Systems Design and Analysis (ESDA 2012), Jul 2012, Nantes, France. pp.ESDA2012-82253. ⟨hal-00714950⟩