CAREER: Exploring Nanoscale Growth Twins for the Development of Grain Boundary Engineering at the Nanoscale

技术概要：晶界工程（GBE）领域已经证明了具有低σ（σ小于或等于29）晶界对于增强材料的物理和化学性能的许多优点。纳米级孪晶晶界的研究允许下一阶段的微结构材料设计的控制和操纵的晶粒和边界在纳米级。因此，本提案的研究目标是双重的：a）通过研究在各种处理条件下形成的缺陷及其与孪晶形成的关系来理解纳米级生长孪晶的演变，以及B）将生长孪晶如何与边界相互作用以产生低西格玛晶界联系起来。为了完成设定的目标，该项目将集中在一些关键方面，如成长孪晶的演变，以提供一个框架，引入纳米级成长孪晶在许多不同的系统，通过使用控制合成方法：磁控溅射。非技术摘要：这项研究提出了一个新的方向，通过引入工程结构，使用传统的材料科学和纳米技术的材料发展。尽管纳米材料已经显示出巨大的潜力，但它们的应用通常存在两个限制因素：热稳定性和低延展性。该研究计划旨在为有望进一步改善纳米结构材料的领域提供基础研究。这种能力可以进一步帮助设计新的耐热涂层和微米和纳米级MEMS系统。此外，该项目的重点是科学，技术，工程和数学（STEM）学习，因为PI将与Iridescent，一个非营利的教育组织，提供高质量，令人兴奋的，现实世界的科学教育，目标是低收入的西班牙裔和非洲裔美国儿童在洛杉矶地区。一个关于绿色材料加工的十次研讨会将由南加州大学PI工程学院新生班为彩虹色项目开发。因此，研究，教学和推广是无缝结合的PI的更广泛的影响的一部分。

TECHNICAL SUMMARY: The field of grain boundary engineering (GBE) has demonstrated the many advantages of having low Sigma; (Sigma less than or equal to 29) grain boundaries for enhanced physical and chemical performance of materials. The study of nanoscale twin boundaries allows for the next stage of microstructural material design by the control and manipulation of both grains and boundaries at the nanoscale. Therefore, the research objective of this proposal is twofold: a) to understand the evolution of nanoscale growth twins by studying the defects formed under various processing conditions and their relationship to twin formation and b) to relate how growth twins interact with boundaries to generate low Sigma grain boundaries. In order to accomplish the set objectives this project will focus on some key aspects such as the evolution of growth twins to provide a framework for the introduction of nanoscale growth twins in many different systems by using a controlled synthesis method: magnetron sputtering.NON-TECHNICAL SUMMARY: This study presents a new direction for materials development by introducing engineered structures using traditional materials science and nanotechnology. Even though nanoscale materials have shown tremendous potential there are typically two limiting factors to their application: thermal stability and low ductility. This research proposal aims to provide fundamental research on an area that promises further improvement of nanostructured materials. This ability can further aid in the design of new thermal resistant coatings and micro- and nano-scale MEMS systems. In addition, this projects focuses on Science, Technology, Engineering and Math (STEM) learning since the PI will work with Iridescent, a non-profit, educational organization, to provide high quality, exciting, real-world science education that targets low-income Hispanic and African-American children in the Los Angeles area. A ten-session workshop on green materials processing will be developed for the Iridescent program by the PI's Engineering Freshman Academy class at USC. Thus, research, teaching and outreach are seamlessly combined as part of the PI's broader impacts.