Lead-free piezoceramic materials for SONAR transducers

压电材料广泛应用于电工技术中，在传感器和执行器中实现电能和机械能的转换。一个重要的应用领域是声学（例如医学超声成像），其中压电材料将电信号转换为声波，反之亦然。这些应用的市场领先材料是锆钛酸铅陶瓷，称为PZT。由于全球立法限制在电子产品中使用铅，PZT可能会过时，并被无铅材料所取代。因此，该项目的目的是确定和优化一种专门用于声纳设备的无铅压电陶瓷。该项目有以下目标：1。与工业赞助商合作，准备声纳设备中无铅压电材料的目标规范。查阅文献，比较主要候选无铅压电材料的性能。准备和测试主要候选材料的例子。根据满足目标规格的潜力，选择一种材料进行进一步开发。通过改变成分，通过掺杂调整缺陷化学，以及改变工艺变量来执行材料优化程序。该项目将采用最新的陶瓷工艺技术和广泛的介电、铁电和压电表征技术，研究材料的组成、加工和性能之间的关系

Piezoelectric materials are widely used in electrotechnology to convert between electrical and mechanical energy in sensors and actuators. An important field of application is acoustics (e.g. medical ultrasound imaging), in which the piezoelectric material converts electrical signals to acoustic waves and vice-versa. The market leading material for these applications is lead zirconate titanate ceramic, known as PZT. Due to the worldwide legislation limiting the use of lead in electronics, there is a possibility that PZT may become obsolete and be replaced with lead-free materials. Hence the aim of this project is to identify and optimise a lead-free piezoelectric ceramic specifically for use in sonar devices. The project has the following objectives:1. In collaboration with the industrial sponsor, prepare a target specification for lead-free piezoelectric materials in sonar devices.2. Survey the literature to compare the properties of the leading candidate lead-free piezoelectric materials.3. Prepare and test examples of the leading candidate materials.4. Select a material for further development based on its potential to meet the target specification.5. Carry out a material optimization programme by varying composition, adjustment of defect chemistry via doping, and variation of process variables.The project will employ the latest ceramic process techniques and a wide range of dielectric, ferroelectric and piezoelectric characterization techniques with which to study the relationship between the composition, processing and properties of the materials