U.S.-Germany Cooperative Research: Rate Effects in the Fracture Toughness of Ferroelectric Ceramics under Mechanical Loading

0129025林奇这个奖项支持克里斯托弗林奇和学生从格鲁吉亚技术在一个合作与于尔根Roedel的材料系在达姆施塔特，德国技术大学。 该国际项目的目标是设计比目前使用的铁电陶瓷更不脆、更可靠的铁电陶瓷。 这将需要详细的知识，准静态和疲劳裂纹性能下的电气和机械负载。 为了改善材料的性能，必须充分了解其失效机制。 该美国小组开发了一种有限元计算机代码，能够确定铁电材料中的应力和电场集中。 该德国团队开发了实验技术和专用夹具，用于测量脆性材料在电和机械载荷组合下的裂纹扩展行为。 通过将两组的优势结合在一起，新的分析技术和新的实验技术将使人们能够充分了解锆钛酸铅（PZT）的断裂过程，这反过来又将阐明微观结构在断裂过程中的作用。 工作计划规定研究生广泛参与国际旅行和研究。

0129025LynchThis award supports Christopher Lynch and students from Georgia Tech in a collaboration with Juergen Roedel of the Department of Material at the Technical University of Darmstadt, Germany. The aim of the international project is to design ferroelectric ceramics that are less brittle and more reliable than those used today. This will require detailed knowledge of both the quasi-static and fatigue crack properties under both electrical and mechanical loading. To improve the materials properties, the mechanisms of their failure have to be fully understood. The US group has developed a finite element computer code capable of determining stress and electric field concentrations in ferroelectric materials. The German group has developed experimental techniques and specialized fixtures for measuring the crack propagation behavior of brittle materials under combined electrical and mechanical loading. By bringing together the strengths of both groups, new analytical techniques and new experimental techniques will make possible a full understanding of the fracture process in lead zirconate titanate (PZT), which in turn will elucidate the role of microstructure in the fracture process. The work plan provides for extensive participation by graduate students in the international travel and research.