超大应变BNT基厚膜叠层无铅压电执行器及其界面调控机理

项目名称： 超大应变BNT基厚膜叠层无铅压电执行器及其界面调控机理

项目编号： No.51202074

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 无机非金属材料学科

项目作者： 张海波

作者单位： 华中科技大学

项目金额： 25万元

中文摘要： 叠层无铅压电执行器环保、位移精度高、响应快、能耗小、驱动电压低应用极为广泛,但是目前所能达到的应变值较小。KNN改性的BNT基无铅压电陶瓷具有0.48%的超大场致应变但需在80kV/cm的高电场下实现,难以实际应用。项目拟采用10-100μm厚的KNN改性BNT基压电厚膜层制备叠层压电执行器，从而在较小的电压下实现极高的场致应变。并在优化界面与微结构参数的前提下，通过调控应力、细化晶粒、减薄压电层等"结构工程"的方法提高压电系数与退极化温度，制备出具有超大应变的无铅叠层压电执行器，为无铅压电器件研发提供了新的思路。采用PFM与XRD原位观测技术对场致相变与非180 电畴翻转进行分析，揭示微观结构、相变与畴变对叠层压电执行器的场致应变的影响规律。建立不同微观结构以及残余应力下的场致相变、畴变与场致应变的理论模型与经验公式,对厚膜叠层无铅压电执行器进行优化设计，具有极大的理论意义与应用价值。

中文关键词： 无铅压电；压电致动器；压电厚膜；钛酸铋钠；电致应变

英文摘要： The lead-free multilayer piezoelectric actuator has the potential of wide application due to the advantages of environment compliance, high displacement resolution, high response speed, low-voltage driving, and low power consumption. However,the field-induced strain is too low for industrial application. Recently, a temperature-insensitive lead-free piezoceramics with giant strain based on KNN modified BNT ceramics have been developed. However,the property of high strain can only be realized at relatively high electric fields exceeding 80 kV/cm. In order to get this giant field-induced strain at very small applied voltage, the BNT-based lead-free thick films with thickness of 10-100μm will be used to fabricate multilayer piezoelectric actuators. Moreover, based on the optimization of the piezoelectric/electrode interfacial layer and structure parameters, the microstructural engineering technologies including the control of residual stress, fining grain size, and reducing thickness of piezoelectric active layer are employed to improve piezoelectric coefficient and depolarization temperature, which shines the research and development of lead-free piezoelectric devices. Furthermore, the planned project will employ PFM and in situ XRD aided with Rietveld Profile Refinement methods to investigate the relationships b

英文关键词： Lead-free piezoelectrics；Piezoelectric actuators；Piezoelectric thick films；Sodium bismuth titanate oxide；Electric-field-induced strain