Densification behaviors of Al2O3 ceramics during flash sintering

Abstract The densification behaviors of MgO‐doped‐Al 2 O 3 ceramics in the flashing stage and the steady stage were investigated using the classic kinetic model. The results show that the most densification of MgO‐doped Al 2 O 3 was completed during the flashing stage. The densification mechanism transferred from particle rearrangement resulted from Columbic force among particles under the effect of electrical field in the flashing stage to the lattice diffusion in the steady stage. Therefore, the densification rate in the steady stage dramatically decreased. Additionally, the estimated densification activation energy in the steady stage of flash sintering is 396 kJ/mol, much lower than the activation densification of lattice diffusion measured from conventional sintering, likely due to the effect of electric field/current‐induced point defects on the diffusion.