综述了反应模板晶粒生长(RTGG)技术和模板晶粒生长(TGG)技术在钙钛矿结构织构陶瓷中的应用,探讨了利用TGG技术制备具有〈001〉取向织构陶瓷的生长机制,并对模板和基料的选择进行了说明:1)模板应选择与基料具有相同晶体结构且晶格失配小于15%的非等轴化学性能随温度变化稳定的片状单晶体;2)从动力学角度分析了TGG过程,基料颗粒越细小,模板形核和取向晶粒生长的驱动力越大。评述了3种具有钙钛矿结构无铅压电织构陶瓷体系(铌酸钾钠基、钛酸钡基、钛酸铋钾钠基)的织构化研究现状和织构陶瓷特点,特别是压电性能改善的途径,并展望了3类具有钙钛矿结构无铅压电陶瓷织构化的发展方向及前景。
This review represented the preparation of perovskite-structured piezoelectric ceramics by reactive templated grain growth (RTGG) method and templated grain growth (TGG) method. The growth mechanism of 〈001〉-textured lead-free ceramics by TGG method as well as the selection of templates and matrix powders were discussed. The plate-like templates have good chemical and thermal stabilities and the same crystal structure with the matrix, and the lattice mismatch is lower than 15%. Based on the kinetic analysis of TGG method, the driving force of nucleation for the templates increases gradually with the decrease in the particle size of matrix powder. This review mainly introduced the development of three types of perovskite-structured lead-flee ceramics, i.e., potassium sodium niobate (KNN)-, bismuth sodium titanate (BNT)-, and barium titanate (BT)-based lead-free ceramics. In addition, the future development of the lead-free textured ceramics was also prospected.