冷烧结钛酸铋钠基陶瓷的热处理工艺研究

Study on Heat Treatment of Cold-Sintering Bismuth Sodium Titanate-Based Ceramics

摘要: 冷烧结技术(CSP)因其极低的烧结温度与较短的烧结时间，成为近年来备受关注的一种高效节能的陶瓷制备方法。但其仍存在致密度不足、可靠性等问题。本文利用化学包覆的方法将耐击穿的SiO₂相引入陶瓷颗粒表面，优化钛酸铋钠基陶瓷的冷烧结性能，并系统研究了不同热处理温度对冷烧结后0.78BNT-0.22NN@SiO₂陶瓷的物相结构、显微形貌及铁电性能的影响。最终，成功制备了相对密度接近99%的冷烧结陶瓷。结果表明，热处理温度为1050℃的冷烧结0.78BNT-0.22NN@SiO₂陶瓷的室温介电常数为1340，介电损耗为1.4%，具有优异的介温稳定性；并且，其室温最大放电储能密度为3.56 J/cm³；样品在1 Hz至100 Hz频率范围内，储能密度变化率仅为3%，表现出了优异的储能性能。

Abstract: Cold sintering process (CSP) has attracted considerable attention in recent years as an efficient and energy-saving method for ceramic preparation due to its extremely low sintering temperature and short sintering time. However, it still faces issues such as insufficient density and reliability. This paper employs a chemical coating method to introduce a breakdown-resistant SiO₂ phase onto the surface of ceramic powders, optimizing the cold sintering performance of Bi_0.5Na_0.5TiO₃(BNT)-based ceramics. The effects of different heat treatment temperatures on the phase structure, microstructure, and ferroelectric properties of cold-sintered 0.78BNT-0.22NN@SiO₂ ceramics have been systematically investigated. As a result, ceramics with a relative density close to 99% were successfully prepared via the CSP with an optimized heat treatment temperature. The results indicate that the cold-sintered 0.78BNT-0.22NN@SiO₂ ceramic heat-treated at 1050˚C has a room temperature dielectric constant of 1340 and a dielectric loss of 1.4%, exhibiting excellent temperature stability of the dielectric properties. Moreover, its maximum discharge energy storage density at room temperature is 3.56 J/cm³, and the energy storage density variation rate is only 3% within the frequency range of 1 Hz to 100 Hz, demonstrating outstanding energy storage performance.