Staged microstructural study of flash sintered titania

Flash sintering offers more control of microstructure owing to its additional sintering conditions compared to conventional sintering, including electric field, current density limit and holding time. A systematic study of flash sintered TiO2 is presented to investigate the effects of flash sintering conditions on the asymmetrical microstructure and defect structure across the two electrodes of the samples. Grain growth has been found to be more prominent near the positive electrode and significantly influenced by the current density limit. Extended defects, including dislocations and stacking faults, have been observed near the positive electrode and the defect density is highly dependent on the strength of electric field. Lowering the current density and holding time could maximize the defect density in TiO2 for improved properties.