Non-thermal effect on densification kinetics during microwave sintering of α-alumina

The microstructural evolution and densification kinetics of a-alumina were investigated and compared between conventional sintering and microwave sintering at 2.45 GHz in the intermediate stage, where the microwave seems to be the most efficient. Based on classical kinetics models, the calculated kinetics parameter demonstrated that the densification is greatly influenced by the presence of an electromagnetic field during sintering. It was assumed that the grain boundary diffusion is enhanced by an electromagnetic pressure induced by the microwave. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.