(Ba,Ca)(Ti,Sn)O3多元体系无铅压电陶瓷的相结构与性能调控研究

(Ba,Ca)(Ti,Sn)O3 based lead-free piezoelectric ceramics have attracted more and more attention because of their exceptionally high piezoelectric properties. However, the phase structure, phase diagram and their relevance to the electrical properties are still not well clear. Besides, under the premise of maintaining a high piezoelectric response, methods to lowering sintering temperatures and enhancing Curie temperature (TC) also need to be intensively researched. In this project, issues involving constituent elements, phase structure, phase diagram as well as electrical properties of (Ba,Ca)(Ti,Sn)O3 based lead-free piezoelectric ceramic system are going to be investigated systematically by widening the composition range. Based on establishing phase diagram of the critical ingredient region, the influencing factors and mechanism of two-phase or multiphase coexistence with T-O/O-R/T-R/T-O-R phase for enhanced piezoelectric and ferroelectric properties will be revealed. To broaden the application fields of (Ba,Ca)(Ti,Sn)O3 based ceramics, the densification sintering temperature will be reduced by adding several kinds of sintering aids and TC will be enhanced by introducing high-TC systems such as BiFeO3.

(Ba,Ca)(Ti,Sn)O3基无铅压电陶瓷异常高的压电活性受到研究者的广泛关注，但是该体系的相结构与相图及其与电学性能的关联性以及在维持高压电响应特性的基础上如何降低烧结温度和提升居里温度TC等问题有待深入研究。本项目拟在拓宽研究(Ba,Ca)(Ti,Sn)O3基无铅压电陶瓷成分范围的基础上，系统研究该陶瓷体系的组元成分、相结构、相图以及电学性能所涉及的科学问题，建立其关键区域的相图，重点揭示T-O/O-R/T-R/T-O-R两相或多相共存的相结构对陶瓷的铁电与压电性能的影响规律与性能增强机理；引入多种助烧剂降低该体系的致密化烧结温度；复合BiFeO3等高TC体系，制备高TC且具有高压电性能的(Ba,Ca)(Ti,Sn)O3无铅压电陶瓷，拓宽高性能 (Ba,Ca)(Ti,Sn)O3无铅压电陶瓷的应用领域。

压电材料能够实现电能和机械能的直接相互转换，在制动器、点火器、传感器等方面有广泛的应用。由于目前占据市场主导地位的锆钛酸铅压电陶瓷含有大量有毒的铅元素对人类健康和自然环境产生巨大危害，因此发展无铅压电陶瓷成为当前迫切需求。(Ba,Ca)(Ti,Sn)O3基无铅压电陶瓷异常高的压电活性受到研究者的广泛关注，但是该体系的相结构与相图及其与电学性能的关联性以及在维持高压电响应特性的基础上如何降低烧结温度和提升居里温度Tc等问题有待深入研究。本项目在拓宽(Ba,Ca)(Ti,Sn)O3基无铅压电陶瓷成分范围的基础上，系统研究了该陶瓷体系的组元成分、相结构、相图以及电学性能所涉及的科学问题，建立了其关键区域的相图，重点揭示了T-O/O-R/T-R/T-O-R两相或多相共存的相结构对陶瓷的铁电与压电性能的影响规律与性能增强机理；研究了Ca2+和Sn4+含量的变化对Tc的影响机理，寻找到了高Tc的组元成分；引入LiF、Li2O、Li2CO3、CuO、B2O3等多种助烧剂降低了该体系的致密化烧结温度，揭示了各种助烧剂的低温致密化烧结机理及性能增强机理；复合了BiFeO3等高Tc体系，制备了高Tc且具有高压电性能的(Ba,Ca)(Ti,Sn)O3无铅压电陶瓷，拓宽了高性能(Ba,Ca)(Ti,Sn)O3无铅压电陶瓷的应用领域。申请国家发明专利1项，参加国际国内学术会议15人次，发表SCI收录论文23篇，其中0<IF<1的4篇，1<IF<3的10篇，3<IF<5的7篇，5<IF的2篇，至目前引用次数共计32次，培养博士生5人，硕士生7人。