A versatile defect engineering strategy for room-temperature flash sintering

In this study, we reported that flash sintering (FS) could be efficiently triggered at room temperature (25 ℃) by manipulating the oxygen concentration within ZnO powders via a versatile defect engineering strategy, fully demonstrating a promising method for the repaid prototyping of ceramics. With a low concentration of oxygen defects, FS was only activated at a high onset electric field of ~2.7 kV/cm, while arcs appearing on the surfaces of samples. Strikingly, the onset electric field was decreased to < 0.51 kV/cm for the activation of FS initiated, which was associated with increased oxygen concentrations coupled with increased electrical conductivity. Thereby, a general room-temperature FS strategy by introducing intrinsic structural defect is suggested for a broad range of ceramics that are prone to form high concentration of point defects.