Rechercher des projets européens

Effect of an External Electric Field on Grain Boundary Evolution in the Course of Nano-Ceramic Sintering (EEEF-GBE-CNS)
Date du début: 1 oct. 2012, Date de fin: 30 sept. 2016 PROJET  TERMINÉ 

"Consolidation of oxide nanoparticles in the presence of an electric field has provided promising results for retaining the nanostructure in the bulk. Although the sintering of nanoparticles shares the same basic principles as those for the sintering of coarser particles, a number of issues and challenges are specific to nanosintering. From a thermodynamic point of view, solid state sintering can be described as a thermally activated process during which the total interfacial free energy of an assembly of particles of equilibrium chemical composition decreases. Moreover, the consolidation and the grain growth pattern are determined by the ratio of the solid-vapour interfacial energy to the solid-solid interfacial (i.e., grain boundary) energy of the material. We propose to take a first step towards elucidating these processes in the presence of an external electric field by testing the synergistic effects of an external electric field and dopants on the grain boundary energy and sintering mechanism of oxide nanoceramics. Our first objective is to study the individual contribution of the dopant on the surface and interfacial energies. We hypothesize that the dopant will significantly affect these energies and thereby change the sintering course. Our second objective is to study the effect of a DC electric field on the dopants, the interfacial and surface energies, the space charge layer, and the grain size of the materials. We will map the contribution of each parameter to the consolidation process. The most promising parameter will be further investigated by studying the properties of the resulting material which is the third objective of this study. The experiments proposed here will increase our understanding of the consolidation mechanism of nanoceramics in the presence of an external electric field."

Coordinateur

Details