Synthesis and Electromechanical Behavior of "Smart" Ferroelectric Ceramics

“智能”铁电陶瓷的合成和机电性能

• 批准号: 9522504
• 负责人: Raj Singh
• 金额: $ 28.5万
• 依托单位: University of Cincinnati Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-02-15 至 2000-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9522504&HistoricalAwards=false
• 关键词: Synthesis; Electromechanical; Behavior; Smart; Ferroelectric

9522504 Singh The objective of the proposed research is to study the effect of the nature and amplitude of cyclic electric fields on crack propagation. Most piezoelectric leadzirconium titanates (PZTs) are used under AC fields, where the combined mechanical and electrical loading can cause component failure. Finite element models developed in the current project will be extended to describe the electromechanical response of PZT under a variety of boundary conditions. In addition, a novel technique of laser Raman spectroscopy (LRS) will be applied to directly measure the distribution of crack tip stresses produced by applied electric fields. The results will be compared with stresses calculated using FEA models. The proposed research objectives will be accomplished by performing in situ crack propagation studies in PZT ceramics under static (DC) and cyclic (AC) electric fields, directly measuring electricallygenerated crack tip stresses in situ using LRS, developing a finite element model to describe the effect of applied electric field on crack propagation, and studying the influence of microstructure and composition on the induced phase transformations in PZT ceramics. %%% These studies will lead to a new and fundamental understanding of the electromechanical response of piezoelectric materials under combined electric and mechanical loads. A new techniques using LRS for directly measuring crack tip stresses will be demonstrated along with the possibilities of induced phase transformation in the strontium-doped PZT system. ***

9522504 Singh 本研究的目的是研究循环电场的性质和幅度对裂纹扩展的影响。 大多数压电钛酸铅锆 (PZT) 在交流场下使用，机械和电气的综合负载可能会导致组件故障。 当前项目中开发的有限元模型将被扩展以描述 PZT 在各种边界条件下的机电响应。 此外，激光拉曼光谱（LRS）新技术将用于直接测量外加电场产生的裂纹尖端应力的分布。 结果将与使用 FEA 模型计算的应力进行比较。 所提出的研究目标将通过在静态（DC）和循环（AC）电场下对PZT陶瓷进行原位裂纹扩展研究，使用LRS直接测量原位电产生的裂纹尖端应力，开发有限元模型来描述施加电场对裂纹扩展的影响，以及研究微观结构和成分对PZT陶瓷中诱导相变的影响来实现。 %%% 这些研究将带来对压电材料在电和机械联合负载下的机电响应的新的、基本的理解。 将展示使用 LRS 直接测量裂纹尖端应力的新技术以及在掺锶 PZT 系统中诱导相变的可能性。 ***