Article ID Journal Published Year Pages File Type
1474493 Journal of the European Ceramic Society 2014 5 Pages PDF
Abstract

Isothermal field-assisted sintering of two-phase, 50 vol% 3YSZ-alumina composites exhibit an incubation time for the onset of the flash event. Weaker applied fields and lower temperatures lengthen the incubation period. The effect is highly non-linear. For example at 1300 °C and 150 V cm−1 the flash occurs nearly instantaneously (in 10 s), but extends to 2 h at 1275 °C and 65 V cm−1. This behavior is reminiscent of nucleation and growth phenomena in chemically driven experiments involving phase transformations in the solid state. Here, a model for nucleation under electrical driving forces, based upon the growth of embryos of colossal permittivity is presented. Nucleation is the precursor to the onset of a flash. Therefore it occurs at the furnace temperature. Joule heating is a consequence of nucleation not the cause of it.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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