SusChEM: Nanoscale Insight into Electric Fatigue of Lead-Free Piezoelectric Ceramics

SusChEM：无铅压电陶瓷电疲劳的纳米级洞察

• 批准号: 1465254
• 负责人: Xiaoli Tan
• 金额: $ 46.28万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1465254&HistoricalAwards=false
• 关键词: SusChEM; Nanoscale; Insight; into; Electric

NON-TECHNICAL DESCRIPTION: Lead interferes with many body processes, including the development of the nervous system, and therefore is particularly toxic to children, and can cause permanent learning and behavior disorders. Regulations restricting lead use, such as enforced recycling of lead-acid batteries of automobiles and the ban of leaded gasoline and lead paint, have greatly reduced lead exposure in the developed world since the 1970s. However, lead is one of the most produced metals in the world and is still widely used in various products. Even today, lead poisoning remains one of the largest environmental medicine problems in terms of numbers of people exposed and the public health toll it takes. In electronic devices and medical instruments, lead is primarily used in piezoelectric elements. These elements convert electrical signals into acoustic signals and are critical for underwater communications and ultrasound medical imaging. To further reduce lead contamination and create a sustainable environment for future generations, currently used lead-containing piezoelectric materials must be replaced by lead-free ones. This project on fundamental research aims to identify environmentally-friendly compositions for the multi-billion dollar piezoelectrics industry. The outcome has the potential to greatly benefit both human health and the environment. TECHNICAL DETAILS: The core elements in piezoelectric devices are made of lead zirconate titanate ceramics, which contain more than 60 wt.% of lead. The toxicity of lead has raised serious environmental concerns and legislations on restriction of its use have driven extensive worldwide research on the development of lead-free piezoelectric materials. Significant progress has been made in the past decade in composition design and processing control and the research community is now being prompted to move these scientific achievements into fruitful environmentally safe products. As such, fundamental issues related to performance stability and device reliability need to be addressed thoroughly and immediately. In real devices during service, these ceramics are almost invariably driven by cyclic electric or mechanical forces, and eventually their performances deteriorate due to fatigue. Electric fatigue degradation is the major concern for stability and reliability of piezoelectric devices utilizing lead-free ceramics. In this project, the researchers at Iowa State are investigating the microstructural mechanisms of electric fatigue through electrically cycling lead-free ceramic specimens inside the transmission electron microscope for the first time. Such innovative in situ studies can identify the primary microstructural feature that leads to fast fatigue degradation and therefore, will help find ways to alleviate the property degradation. Lead-free compositions can then replace lead zirconate titanate in a wide range of engineering and medical technologies, which greatly help to create a sustainable future for children. This project is also designed to have a broad impact on graduate and undergraduate education by training students in cutting-edge materials research techniques. Furthermore, an App for iPads on the toxicity of lead is under development for demonstrations to high school students and undergraduate students.

非技术描述：铅会干扰许多身体过程，包括神经系统的发展，因此对儿童特别有毒，可能导致永久的学习和行为障碍。自1970年代以来，限制铅使用铅的法规，例如强迫汽车的铅酸电池回收以及禁令禁止铅汽油和铅涂料。但是，铅是世界上生产最多的金属之一，并且仍然在各种产品中广泛使用。即使到了今天，就暴露的人数及其带来的公共卫生损失而言，铅中毒仍然是最大的环境医学问题之一。在电子设备和医疗仪器中，铅主要用于压电元素。这些元素将电信号转换为声学信号，对于水下通信和超声医学成像至关重要。为了进一步减少铅污染并为子孙后代创造可持续的环境，当前使用的含铅压电材料必须由无铅的压电材料代替。该基础研究项目旨在确定数十亿美元压电行业的环保作品。结果有可能极大地使人类健康和环境受益。技术细节：压电设备中的核心元素是由铅锆酸钛酸陶瓷制成的，其中包含超过60 wt的铅。铅的毒性引起了严重的环境问题，并对限制其使用的立法引发了有关无铅压电材料发展的全球广泛研究。在过去的十年中，在组成设计和处理控制方面取得了重大进展，现在正在促使研究界将这些科学成就转移到富有成果的环境安全产品中。这样，与性能稳定性和设备可靠性有关的基本问题需要立即彻底解决。在服务过程中，这些陶瓷几乎总是由环状电或机械力驱动，最终由于疲劳而导致其性能恶化。电疲劳降解是利用无铅陶瓷的压电设备的稳定性和可靠性的主要关注点。在这个项目中，爱荷华州的研究人员首次通过无电气循环陶瓷标本来研究电疲劳的微观结构机制。这种创新的原位研究可以识别导致快速疲劳降解的主要微观结构特征，因此将有助于找到减轻该财产降解的方法。然后，无铅构图可以在广泛的工程和医疗技术中取代铅锆钛酸钛酸钛酸盐，这极大地有助于为儿童创造可持续的未来。该项目还旨在通过培训学生的尖端材料研究技术对研究生和本科教育产生广泛的影响。此外，iPad的应用程序正在开发有关铅的毒性，以向高中生和本科生进行示范。

项目成果

In-situ TEM study of the aging micromechanisms in a BaTiO3-based lead-free piezoelectric ceramic

• DOI: 10.1016/j.jeurceramsoc.2018.03.049
• 发表时间: 2018-08
• 期刊: Journal of the European Ceramic Society
• 影响因子: 5.7
• 作者: Z. Fan;X. Tan

A comparative study of the polarization degradation mechanisms during electric cycling in (Bi1/2Na1/2)TiO3-based relaxors

• DOI: 10.1016/j.scriptamat.2019.11.061
• 发表时间: 2020-03
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: Z. Fan;X. Tan

Phase-composition dependent domain responses in (K0.5Na0.5)NbO3-based piezoceramics

• DOI: 10.1016/j.jeurceramsoc.2019.11.046
• 发表时间: 2020-04-01
• 期刊: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
• 影响因子: 5.7
• 作者: Fan, Zhongming;Zhang, Shujun;Tan, Xiaoli
• 通讯作者: Tan, Xiaoli

Dual-stimuli in-situ TEM study on the nonergodic/ergodic crossover in the 0.75(Bi 1/2 Na 1/2 )TiO 3 –0.25SrTiO 3 relaxor

0.75(Bi 1/2 Na 1/2 )TiO 3 →0.25SrTiO 3 弛豫器非遍历/遍历交叉的双激励原位TEM研究

• DOI: 10.1063/1.5093510
• 发表时间: 2019
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Fan, Zhongming;Tan, Xiaoli
• 通讯作者: Tan, Xiaoli