Dynamic grain growth during low-temperature spark plasma sintering of alumina

An existing defect model for dynamic grain growth is modified in order to incorporate the role of grain-boundary sliding on the generation of defects during sintering. On the basis of the concept of enhanced defect generation, the unusual grain growth of alumina during spark plasma sintering is discussed in correlation with the densification caused by grain-boundary sliding. The modified model explains well the experimentally observed dependence of grain size on pressure, heating rate and loading schedule. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.