Electric forces effect on field-assisted sintering

Abstract

Electric forces acting on crystallographic defects generated at the flash onset or due to the surface polarization of the dielectric surrounding pores have been claimed to interact with the sintering kinetics upon flash processes. Herein, we estimated the magnitude of the external field-induced forces pointing out that the surface polarization does not play significant role on sintering. Moreover, the electric forces acting on charged defects are negligible when compared with the sintering stresses in the majority of flash experiments, only becoming comparable with the capillarity pressures when the external field is in the order of 103 V cm−1. Therefore, they can be of some relevance during flash sintering of resistive compounds like alumina or silicate glasses, they remaining normally not relevant otherwise.