FRG: Domain Orientation and Anisotropy in Poled Piezoelectrics

FRG：极化压电体中的磁畴取向和各向异性

• 批准号: 0805022
• 负责人: Keith Bowman
• 金额: $ 87.8万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0805022&HistoricalAwards=false
• 关键词: FRG; Domain; Orientation; Anisotropy; Poled

NON-TECHNICAL DESCRIPTION Piezoelectric materials are critical for applications in sensors and actuators that enable medical ultrasound, therapies that promote bone healing, highly efficient portable power transformers, high performance diesel engines and many other applications involving conversion between electrical and mechanical energy. The goal of this research team is to improve our understanding of piezoelectrics by fully optimizing existing materials and enabling enhanced potential for industrial development of environmentally friendly, lead free piezoelectrics. The research project will also be directed towards developing educational materials on the science and engineering of piezoelectrics for students from middle school to beginning college. The educational materials will be used to enhance skill development in math and science and to foster interest in science and engineering. TECHNICAL DETAILS: Exploration of crystallographic texture with domain orientation and anisotropy in poled, lead free piezoelectrics enables understanding of the interrelationships between texture and microstructure that can lead to replacement of lead-containing piezoelectrics. This project will couple domain textures and crystallographic textures in bulk materials to understand the development of piezoelectric and other anisotropic properties. Effects of poling field, poling temperature, conductivity and intrinsic materials properties such as electrical and thermal conductivity, elasticity and thermal expansion are critical aspects for developing this understanding. The project consists of development of processing approaches to produce bulk materials that can be used to fully describe the interplay between texture and anisotropy in the rapidly evolving classes of lead free piezoelectric materials. Project investigators are considering nanoscale and microscale interactions between ferroelastic and ferroelectric domains across grain boundaries as a function of stress state, temperature and processing history via scanned surface probe techniques. The experimental aspects are pivotal to describing the relationship of texture and microstructure to properties for comparison to incisive microstructure-based numerical simulations that capture the thermodynamics and physics occurring on the scale of the domains and grains. Both the experimental and computational aspects of this project will be carried out in collaboration with colleagues in the automobile and diesel engine industries and at the Technical University of Darmstadt. This project is producing a better understanding of poling processes, the limitations imposed on poling by the underlying ferroelastic and ferroelectric domains and their interactions with grain boundaries and microstructure. Undergraduate and graduate student researchers are learning advanced techniques for numerical simulation of nanoscale and microscale effects on properties, sample preparation techniques for surface probe analysis and electron microscopy, surface probe techniques, electron microscopy and x-ray and neutron diffraction techniques.

非技术描述压电材料对于传感器和执行器中的应用至关重要，这些传感器和执行器可实现医疗超声、促进骨骼愈合的治疗、高效便携式电源变压器、高性能柴油发动机以及涉及电能和机械能之间转换的许多其他应用。 该研究团队的目标是通过充分优化现有材料并增强环保、无铅压电材料的工业发展潜力，提高我们对压电材料的了解。 该研究项目还将致力于为中学生到大学新生开发压电科学与工程的教育材料。 这些教育材料将用于增强数学和科学技能的发展，并培养对科学和工程的兴趣。技术细节：探索极化无铅压电体中具有畴取向和各向异性的晶体织构，有助于了解织构和微观结构之间的相互关系，从而替代含铅压电体。该项目将耦合散装材料中的域纹理和晶体纹理，以了解压电和其他各向异性特性的发展。 极化场、极化温度、电导率和固有材料特性（例如电导率和导热率、弹性和热膨胀）的影响是发展这种理解的关键方面。该项目包括开发生产散装材料的加工方法，这些材料可用于充分描述快速发展的无铅压电材料类别中纹理和各向异性之间的相互作用。 项目研究人员正在通过扫描表面探针技术考虑铁弹性域和铁电域之间跨越晶界的纳米级和微米级相互作用，作为应力状态、温度和加工历史的函数。 实验方面对于描述纹理和微观结构与性能的关系至关重要，以便与基于微观结构的深入数值模拟进行比较，这些数值模拟捕获域和晶粒尺度上发生的热力学和物理现象。该项目的实验和计算方面都将与汽车和柴油发动机行业以及达姆施塔特工业大学的同事合作进行。 该项目正在更好地了解极化过程、底层铁弹性和铁电域对极化施加的限制以及它们与晶界和微观结构的相互作用。本科生和研究生研究人员正在学习纳米尺度和微米尺度对性能影响的数值模拟的先进技术、表面探针分析和电子显微镜的样品制备技术、表面探针技术、电子显微镜以及 X 射线和中子衍射技术。