Fundamental Insights into Multi-element Grain Boundary Segregation in Nanocrystalline Alloys

纳米晶合金中多元素晶界偏析的基本见解

• 批准号: 2343682
• 负责人: Fadi Abdeljawad
• 金额: $ 25.79万
• 依托单位: Lehigh University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2343682&HistoricalAwards=false
• 关键词: Fundamental; Insights; into; Multi; element

NONTECHNICAL SUMMARYThis award supports research and educational activities aimed at gaining fundamental insights into the segregation of multiple elemental species to grain boundaries, and how it affects grain growth in nanocrystalline metallic alloys. Nearly all functional and structural materials are polycrystalline systems; they are composed of differently oriented crystalline grains that are joined at internal interfaces, termed grain boundaries. The grain size and distribution in a metal greatly influences many engineering properties, including mechanical, thermal, and electrical. For example, the mechanical strength of a metal increases rapidly with decreasing grain size. However, due to their small grain size and high density of grain boundaries, nanocrystalline materials are usually structurally unstable. As a result, they undergo rapid grain growth, which limits their use in many technological applications. In this project, the PI will investigate the segregation of multiple types of elemental species to grain boundaries and its role in grain growth in multi-component alloys. The research involves theoretical development and numerical implementation of mathematical models that will be used to simulate the dynamics of grain boundary segregation and grain growth kinetics. A primary focus of this project will be on metallic alloys composed of three different types of elements. Lying at the intersection of materials science and applied mathematics, this project will impact numerous areas of materials physics, chemical thermodynamics, and nanotechnology. Further, this project will provide an avenue to train future-generation of engineers and scientists with the skill set necessary for careers in knowledge-intensive industries in South Carolina, which is an emerging technology and manufacturing hub. The PI will design an “Atomic Legos” outreach activity to engage K-12 students in materials science and help them learn about crystals and metals. This project leverages Clemson’s “Creative Inquiry” program in order to involve undergraduate students, particularly women and underrepresented groups, in scientific research.TECHNICAL SUMMARYThis award supports the development of a mesoscale theoretical and computational modeling framework aimed at advancing our fundamental understanding of the segregation of multiple types of elemental species to grain boundaries and its role in grain growth and thermal stability of nanocrystalline metallic alloys. Owing to their nanoscale grain size, nanocrystalline materials exhibit a unique combination and properties and functionalities. However, rampant grain growth during materials processing or under service conditions is considered one of the main hurdles to the large-scale use of nanocrystalline metals in many engineering technologies. In this project, the PI aims to elucidate key multi-element grain boundary segregation mechanisms that control grain boundary migration and grain growth in metallic alloys. Specific goals of this project include: (1) Development of a theoretical and computational phase field model of multi-element grain boundary segregation in multi-component alloys that accounts for bulk and interface thermodynamics and is able to simulate the microstructural evolution over diffusive scales; (2) Perform theoretical analysis and computational studies to quantify the thermodynamic and kinetic effects of multi-element grain boundary segregation on the thermal stability of nanocrystalline alloys; (3) Quantify the role of the grain boundary network effect in solute partitioning and distribution within grain microstructures. Lying at the intersection of materials science and applied mathematics, this project will impact numerous areas of materials physics, chemical thermodynamics, and nanotechnology. Further, this project will provide an avenue to train future-generation of engineers and scientists with the skill set necessary for careers in knowledge-intensive industries in South Carolina, which is an emerging technology and manufacturing hub. The PI will design an “Atomic Legos” outreach activity to engage K-12 students in materials science and help them learn about crystals and metals. This project leverages Clemson’s “Creative Inquiry” program in order to involve undergraduate students, particularly women and underrepresented groups, in scientific research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术摘要该奖项支持研究和教育活动，旨在深入了解多种元素在晶界的偏析，以及它如何影响纳米晶金属合金中的晶粒生长。几乎所有功能和结构材料都是由不同组成的多晶系统。在内部界面（称为晶界）处连接的定向晶粒，金属中的晶粒尺寸和分布极大地影响许多工程性能，包括机械、热和电性能。金属的晶粒尺寸随着晶粒尺寸的减小而迅速增加，然而，由于纳米晶材料的晶粒尺寸小且晶界密度高，因此它们在结构上通常不稳定，因此它们会经历快速的晶粒生长，这限制了它们在许多技术应用中的使用。在该项目中，PI 将研究多种元素在晶界的偏析及其在多组分合金晶粒生长中的作用。该研究涉及用于模拟动力学的数学模型的理论开发和数值实现。晶界偏析和晶粒该项目的主要重点是由三种不同类型元素组成的金属合金，该项目位于材料科学和应用数学的交叉点，将进一步影响材料物理、化学热力学和纳米技术的众多领域。该项目将为培养未来一代工程师和科学家提供一个途径，让他们掌握南卡罗来纳州知识密集型行业职业所需的技能。南卡罗来纳州是一个新兴的技术和制造中心，PI 将设计一个“原子乐高积木”。外展活动以吸引材料科学领域的 K-12 学生，帮助他们了解晶体和金属。该项目利用克莱姆森大学的“创意探究”计划，让本科生，特别是女性和弱势群体参与科学研究。技术摘要该奖项支持开发一个项目。介观理论和计算建模框架旨在增进我们对多种元素种类在晶界的偏析及其在纳米晶金属合金的晶粒生长和热稳定性中的作用的基本理解。由于其纳米级晶粒尺寸，纳米晶材料表现出独特的组合、性能和功能，然而，材料加工过程中或使用条件下晶粒的猖獗生长被认为是纳米晶金属在许多工程技术中大规模使用的主要障碍之一。在该项目中，PI 旨在阐明控制金属合金中晶界迁移和晶粒生长的关键多元素晶界偏析机制。该项目的具体目标包括：（1）开发理论和计算方法。多组分合金中多元素晶界偏析的相场模型，能够解释体积和界面热力学，并能够模拟扩散尺度上的微观结构演化；（2）进行理论分析和计算研究，以量化热力学和动力学效应；多元素晶界偏析对纳米晶合金热稳定性的影响；（3）量化晶界网络效应在晶粒微观结构内溶质分配和分布的作用。材料科学和应用数学，该项目将影响材料物理、化学热力学和纳米技术的众多领域。此外，该项目还将为培养下一代工程师和科学家提供知识密集型职业所需的技能。南卡罗来纳州是一个新兴的技术和制造中心，PI 将设计一项“原子乐高”推广活动，吸引 K-12 学生学习材料科学，并帮助他们了解晶体和金属。该项目利用了克莱姆森大学的“创意”。 “探究”计划旨在让本科生，特别是女性和弱势群体参与科学研究。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。