A theoretical analysis of cold sintering

Cold sintering is an innovative low-temperature processing technique which allows consolidation of several ceramics. Despite recent research activities on the cold sintering of functional and structural ceramics, an analytical study accounting for consolidation and grain growth phenomena is still missing in the literature. In this work, we provide a theoretical analysis of the mechanisms active during cold sintering. The analysis considers two cold sintering approaches, characterised by the application either of isostatic or uniaxial pressure. Physical phenomena and microstructural features are discussed in view of the applied cold sintering approach. The developed pressure-assisted densification models indicate that the processes governing densification during uniaxial cold sintering are more complex than those of conventional liquid phase sintering. A key role is played by the water/material interaction which promotes several effects such as formation of surface defects and secondary phases, dynamic recrystallization and other phenomena still partially unknown.