Acoustic emission studies of the breakdown of beta-alumina under conditions of sodium ion transport

Abstract

The breakdown of the ceramic electrolyte beta-alumina during the transport of sodium ions has been investigated using an acoustic emission probe. A characteristic feature associated with the onset of electronic conduction through the electrolyte is the presence of sodium metal filaments penetrating the ceramic. The results of this preliminary investigation indicate that the ceramic undergoes a mechanical deterioration which depends on current density, and that the final stage of breakdown is subcritical crack growth.