冷烧结技术的研究进展及其在电工领域的潜在应用

A high sintering temperature of more than 1 000℃ is typically needed for the densification of ceramic materials, which can bring about a great challenge on the phase stability, grain boundary control and co-sintering of ceramic matrix composites. Recently, an extremely low sintering technique named cold sintering process (CSP) was proposed, which refers to a pressure-assisted transient liquid phase sintering process to effect densification by a mediated dissolution-precipitation process at ≤300℃. CSP shows a significant advantage in the sintering of ceramics due to the low-temperature and time-saving characteristics. In this work, the research progress of CSP was reviewed based on the sintering mechanism and its applications in electrotechnical fields. Firstly, the densification process and preparation technology of the CSP ceramics were introduced. Then, the categories of the transient liquid phases, and their roles in the CSP were analyzed. Moreover, the applications of CSP in new electric materials such as ceramic-polymer composites (varistors, pyroelectricity, electrolyte), ceramic-2D materials (pyroelectricity), high-gradient ZnO varistors and ceramic-metal multilayer structures (capacitor) were presented. Finally, the combination of CSP with other sintering techniques were discussed. CSP provides a scientific reference for the study of sintering mechanism at extreme low temperatures, and a new route for the development of novel functional ceramics and ceramic-based composites applied in electrotechnical fields.