Predicting grain size distributions in perovskite-structured Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3–δ oxygen transport membranes

Abstract

This study is conducted over a 3 × 3 time–temperature matrix on Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ (BSCF) ceramics, and sintered bodies above 93% dense are obtained. The electron backscatter diffraction band contrast micrographs of the polished sintered samples are analysed for characterising the grain size distributions (GSDs). This study develops an algorithm for predicting the GSDs of BSCF dependence of sintering condition (time and temperature). In addition, the GSDs predicted by the algorithm agree reasonably with those experimentally observed. When individual grain size is non-dimensionalised by the median grain size, the GSDs data of all BSCF samples reduce to a single self-similar GSD curve. The median grain size is predicted by the classical kinetics equation, Dⁿ= tK₀exp(−Q/RT).