Fundamental mechanisms of removal of stacking fault tetrahedra by mobile low energy boundaries

移动低能边界去除堆垛层错四面体的基本机制

• 批准号: 1304101
• 负责人: Xinghang Zhang
• 金额: $ 44.89万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1304101&HistoricalAwards=false
• 关键词: Fundamental; mechanisms; removal; stacking; fault

TECHNICAL SUMMARY: The objective of this work is to understand the fundamental mechanisms through which mobile twin boundaries (TBs) actively engage and rapidly remove stacking fault tetrahedra (SFTs). The ultimate goal is to design advanced metallic materials that can effectively remove SFTs at low-to-intermediate temperatures. SFTs are detrimental defects in neutron or proton irradiated structural metallic materials with face-centered-cubic structures as they can induce significant hardening and swelling. The PI will use a combination of in situ radiation and in situ nanoindentation technique to investigate the interaction of SFTs with TBs. These studies can explain the annihilation of SFTs by TBs and provide crucial information to validate annihilation mechanisms predicted by MD simulations. Also significant mobility of TBs may make them attractive candidates to remove radiation induced immobile defects, such as SFTs. NON-TECHNICAL SUMMARY:If successful, the benefits of this research will include discovery of important criteria for the design of swelling resistant structural materials for next generation nuclear reactors, and offer the basis for further exploration of physics of radiation induced twin boundary migrations. This project will provide research training to graduate and undergraduate students at Texas A&M University (TAMU). Special effort will be made to recruit female and other minority students through the "Pathway to Ph.D program" funded by TAMU. The project will also enhance the materials science and nanoengineering curricula by incorporating relevant results into classes when introducing advanced nanomaterials, and benefit the new formed Department of Materials Science and Engineering. The PI will disseminate results to a much broader audience by involving high school teachers in the research project through NSF-RET program, and attending international conferences. Collaborations with McMaster University and several DOE National Laboratories will offer graduate students summer research experience.

技术摘要：这项工作的目的是了解移动双界（TBS）积极参与并迅速消除堆叠断层四面体（SFTS）的基本机制。最终目标是设计高级金属材料，这些材料可以在低到中间的温度下有效地去除SFT。 SFT是带有面部中心地带结构的中子或质子辐照的结构金属材料中的有害缺陷，因为它们可以诱导明显的硬化和肿胀。 PI将使用原位辐射和原位纳米识别技术的组合来研究SFTS与TBS的相互作用。这些研究可以解释TBS对SFT的歼灭，并提供至关重要的信息以验证MD模拟预测的歼灭机制。 TBS的显着迁移率也可能使它们具有吸引力的候选者，以消除辐射引起的固定缺陷，例如SFT。非技术摘要：如果成功的话，这项研究的好处将包括发现为下一代核反应堆设计溶胀结构材料的重要标准，并为进一步探索辐射诱导的双边界迁移的物理学提供了基础。该项目将为德克萨斯A＆M大学（TAMU）的研究生和本科生提供研究培训。将通过由TAMU资助的“通往博士学位课程的途径”招募女性和其他少数民族学生的特殊努力。该项目还将在引入高级纳米材料时将相关结果纳入类，并使新成立的材料科学与工程系受益，从而增强材料科学和纳米工程课程。 PI将通过NSF-RET计划参与研究项目并参加国际会议，将结果传播给更广泛的受众。与麦克马斯特大学和多家国家实验室的合作将为研究生提供夏季研究经验。