Nano-mechanical Properties of Grain Boundaries

晶界的纳米力学特性

• 批准号: 0625650
• 负责人: Md Haque
• 金额: $ 25万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-01-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0625650&HistoricalAwards=false
• 关键词: Nano; mechanical; Properties; Grain; Boundaries

NSF Proposal 0625650: Nano-mechanical Properties of Grain BoundariesPI: Md A Haque, the Pennsylvania State University, University Park, PA Abstract: More than 50 years of research on grain boundaries has established their impact on the overall strength of materials, yet experimental studies on their yield strength or Young's modulus are rare in the literature. This is because grain boundaries are random networks of interfaces that are only a few nanometers wide and cannot be isolated and characterized by conventional tensile, bending, indentation tools. This project aims to address this challenge by developing an experimental setup using micro-electro-mechanical (MEMS) force and displacement sensors and in-situ transmission electron microscopy (TEM). Since TEM renders the microstructures visible, the experimental setup will allow simultaneous characterization of crystallographic orientations, crack propagation and plastic deformation mechanisms with atomic resolution. Models based on interfacial fracture mechanics will be developed to extract the grain boundary properties from the experimental data. The fundamental understanding on the interfaces in materials will impact grain boundary engineering, an evolving research direction towards optimized materials design. The project will integrate research and education on mechanics, microscopy and micro/nanotechnology at graduate, undergraduate and K-12 levels while promoting diversity. The research outcomes will be disseminated through conferences and journal articles. One female/minority undergraduate student will be involved through collaboration with the Penn State Minority in Engineering Program. A graduate course titled Mechanics of Nano Materials will be developed and offered. With supplemental funding, two outreach programs will be executed: (1) 'Microscopy for K-12' where local elementary, middle and high school students will operate an electron microscope and (2) Two-week long summer workshop for K-12 teachers.

NSF提案0625650：纳米力学性能的晶界PI：MD A哈克，宾夕法尼亚州州立大学，大学公园，PA摘要：超过50年的晶界研究已经建立了它们的影响，对材料的整体强度，但其屈服强度或杨氏模量的实验研究是罕见的文献。这是因为晶界是只有几纳米宽的界面的随机网络，并且不能通过传统的拉伸、弯曲、压痕工具来隔离和表征。该项目旨在通过开发一种使用微机电（MEMS）力和位移传感器以及原位透射电子显微镜（TEM）的实验装置来应对这一挑战。由于TEM使微观结构可见，实验装置将允许同时表征晶体取向，裂纹扩展和塑性变形机制与原子分辨率。将开发基于界面断裂力学的模型，以从实验数据中提取晶界特性。 对材料界面的基本理解将影响晶界工程，这是一个不断发展的优化材料设计的研究方向。该项目将在研究生，本科生和K-12水平整合力学，显微镜和微/纳米技术的研究和教育，同时促进多样性。研究成果将通过会议和期刊文章传播。一名女性/少数民族本科生将通过与宾夕法尼亚州立大学少数民族工程项目的合作参与。将开发和提供题为纳米材料力学的研究生课程。有了补充资金，将执行两个推广方案：（1）"K-12显微镜“，当地小学、初中和高中学生将操作电子显微镜，（2）为K-12教师举办为期两周的暑期讲习班。