Stability and Dynamics of Mesoscale Microstructure

介观微观结构的稳定性和动力学

• 批准号: 9633719
• 负责人: Long-Qing Chen
• 金额: $ 21.5万
• 依托单位: Pennsylvania State Univ University Park
• 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: 1996-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9633719&HistoricalAwards=false
• 关键词: Stability; Dynamics; Mesoscale; Microstructure

9633719 Chen Theoretical studies will be made of the stability and dynamic evolution of mesoscopic microstructures during phase transformations and materials processing. The main objective is to develop a unified model which can efficiently be employed to study not only the multi-domain structures with competing short- and long-range interactions in a single crystal, but also the multi-grain and multi- phase microstructures in ceramic materials of technological interest. A continuum field approach is used and three specific problems will be investigated: domain formation and dynamics in ferroelectric oxides as a result of competing electrostatic energy, elastic energy and domain wall energy; the formation of nanoscale ordered domains in relaxor ferroelectrics; and, the kinetics of microstructural evolution in multi-grain materials driven by the reduction in the total interfacial energy. %%% This grant studies an important fundamental problem in materials research which has critical technological implications. Namely, analytical and numerical methods will be used to study and understand the evolution of microstructure in materials as they go through changes in phase. This is an extremely difficult fundamental problem which directly impacts materials processing. The particular systems to be studied are ceramic materials in which control of the microstructure has direct bearing on material proerties. Of special interest in this research will be ferroelectric materials which have applications as sensors and optical components. ***

9633719 Chen 对相变和材料加工过程中细观微观结构的稳定性和动态演化进行理论研究。 主要目标是开发一个统一的模型，该模型不仅可以有效地用于研究单晶中具有竞争性短程和长程相互作用的多域结构，而且还可以研究陶瓷中的多晶粒和多相微观结构。具有技术意义的材料。 使用连续场方法，将研究三个具体问题：由于竞争静电能、弹性能和畴壁能量而导致铁电氧化物中的畴形成和动力学； 弛豫铁电体中纳米级有序域的形成；以及由总界面能降低驱动的多晶粒材料的微观结构演化动力学。 %%% 这项资助研究了材料研究中的一个重要的基本问题，具有关键的技术意义。 也就是说，分析和数值方法将用于研究和理解材料在经历相变时微观结构的演变。 这是一个极其困难的基础问题，直接影响材料的加工。 要研究的特定系统是陶瓷材料，其中微观结构的控制对材料性能有直接影响。 这项研究特别感兴趣的是具有传感器和光学元件应用的铁电材料。 ***