A dynamic bifurcation criterion for thermal runaway during the flash sintering of ceramics

作者：da Silva Joao Gustavo Pereira; Al Qureshi Hazim Ali; Keil Frerich; Janssen Rolf^*

来源：Journal of the European Ceramic Society, 2016, 36(5): 1261-1267.

DOI：10.1016/j.jeurceramsoc.2015.11.048

In this paper the densification of ceramics under flash sintering is modelled using an approach based on the heat equation coupled with a apparent activation energy kinetic equation for densification, leading to a system of nonlinear differential equations. Methods to analyse the system either by numerical solutions or via bifurcation theory are presented. Measurements needed to estimate sintering kinetic parameters are executed. The model shown explains the two main features of flash sintering: A characteristic electrical field threshold independent on the temperature, and an incubation time to flash sintering. The results are in agreement with experimental results obtained for Yttria Stabilzed Zirconia and for nano sized BaTiO3. It confirms that the critical condition for the Flash phenomenon is rather the temperature dependent resistivity than the sintering kinetics.

• 出版日期2016-4