Review of flash sintering with strong electric field

Abstract

Abstract Flash sintering is a novel field‐assisted sintering technology for ceramics that allows a dramatic reduction in processing time and temperature. Since 2010, when flash sintering was first reported, it has been a focus of research interest in the field of materials science. Recent study results have confirmed that the sintering temperature decreases with the strength of the applied electric field; for some ceramics, the sintering temperature can be lowered even to room temperature. This represents an innovative breakthrough for ceramic sintering at ultra‐low temperatures. However, once the electric field strength in flash sintering is increased, new questions and challenges arise, such as whether or not partial discharge occurs in the green body if under electro‐thermal coupling stress, how to quantitatively analyse the impact of discharge on sintering, and, moreover, whether the sintering mechanism under a strong electric field is consistent with that under a weak electric field. These research questions require knowledge of partial discharge detection, dielectric theory, and other topics that are beyond the scope of materials science. To address this need, this review summarises the work carried out in flash sintering with a strong electric field from the perspective of high voltage and insulation technology. First, the flash sintering process and mechanism are briefly introduced. Then, the published literature on flash sintering with a strong electric field for various ceramic materials is summarised in depth. In addition, experimental phenomena that are observed in flash sintering with a strong electric field, such as flash and blackening, are discussed. Finally, some suggestions for future work are presented. It is anticipated that the knowledge gap between different areas of study can be filled by this review.