高性能KNN基无铅压电陶瓷的相结构设计与温度稳定性调控

项目名称： 高性能KNN基无铅压电陶瓷的相结构设计与温度稳定性调控

项目编号： No.51302144

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 王轲

作者单位： 清华大学

项目金额： 25万元

中文摘要： 基于环境保护的迫切要求，高性能(K,Na)NbO3（简称KNN）基无铅压电陶瓷的研发引起了人们极大的兴趣。许多研究者指出，在该体系中难以同时获得高压电活性与较好的温度稳定性。我们最近的研究发现，掺杂适量CaZrO3可以使KNN陶瓷的压电常数d33在室温条件下达到320～360pC/N，并且其场致应变在室温至175摄氏度的宽温度范围内变化率小于10%。本课题计划探索CaZrO3含量影响相结构变化及铁电压电性能、温度稳定性的内在作用机理，获取通过相结构设计调控KNN基陶瓷温度稳定性的可行性原则。在此基础上，系统研究不同掺杂元素或化合物改性的KNN基陶瓷的相结构与物理性能，力图得到该体系相结构特征与温度稳定性关联的规律。此外，还将积极探索外加电场、力场调控及微观形貌结构与温度稳定性的联系。这些工作将为KNN基无铅压电陶瓷材料的综合性能优化及进一步发展提供必要的实验基础。

中文关键词： 压电；无铅；铌酸钾钠；温度稳定性；

英文摘要： Although piezoelectric materials have been in commercial use for a long time, the development never ceases during the last few decades. One of the most concerning subjects is searching for lead-free counterparts to substitute the widely used lead zirconate titanate ceramics, which are not environment-friendly. The breakthrough on textured (K, Na)NbO3 (KNN) based ceramics with co-dopants of Li, Ta, and Sb has made a significant impact on the development of lead-free piezoelectric ceramics. In recent years, tremendous studies have been devoted to KNN-based ceramics with emphases on property enhancement by optimizing sintering processes and compositional modifications. However, it seems that the present situation could not fully qualify KNN-based ceramics as a successful alternative for PZT, due to several drawbacks, one of which is the poor thermal stability. Several methods have been propsed for conquring this issue, while it still annoys the community that high piezoelectric properties and decent thermal stability could not be achived simutaneously. The current proposal considers a noval solution for this problem, which takes account of orthorthombic-tetragonal coexsitence as a guarantee for enhanced piezoelectric activity. Based on this designation, temperature-insensitivity may be reallized by means of phase s

英文关键词： Piezoelectric；Lead-free；KNN；Temperature-stability；