Thermodynamics of Interfaces: Theory to Atomistic Modeling

该奖项支持材料界面特性的理论和计算研究和教育。界面无处不在，在许多自然现象中都很重要，例如材料如何破裂和变形，因此在许多科学和技术领域发挥着重要作用。该项目的目标是促进对温度、化学成分、界面形状和其他因素对界面性质的影响的基本理解。实现这一目标的主要方法是将一般理论分析与计算机模拟紧密结合。该研究将为开发界面属性和界面控制过程的新模型提供理论框架，并将为其计算预测提供新的能力。这种改进的理解将增强我们控制许多技术上重要材料的材料性能的能力，包括许多种类的合金和纳米线。进一步为新型纳米结构材料的设计提供理论基础。该项目预计将对材料科学、物理、化学和生物学的几个领域产生影响。PI将把部分研究成果纳入乔治梅森大学（George Mason University）的课程和学生项目，并向当地高中学生作报告，作为其推广工作的一部分。该奖项支持材料界面热力学性质的理论和计算研究和教育。界面在材料断裂、变形等自然现象中无处不在，具有重要意义，因此在许多科学技术领域发挥着重要作用。本项目旨在促进对界面热力学的基本认识，研究温度、化学成分、界面曲率等因素对界面性质的影响。本项目将开展四个研究方向：(1)研究金属晶界（GBs）的结构相变，包括构建GBs相图；(2)合金GBs在接近熔点高温下的组织和性能研究；(3)分析界面性质的平衡热波动，开发界面性质计算预测的有效方法；(4)强弯曲界面热力学的发展，包括将现有理论扩展到非球面界面，并纳入曲率中的二次和高阶效应。原子模拟将利用分子动力学、蒙特卡罗和其他技术。该研究将为相和界面稳定性、相成核和其他界面控制过程的新模型的发展提供理论框架。该项目将有助于更好地理解界面热力学的基本原理，并将为其计算预测提供新的能力。对界面热力学的进一步理解将增强我们控制结构材料的析出和粗化的能力，如高温合金、铸造合金的凝固组织、纳米线生长和反应性润湿。该项目预计将对材料科学、物理、化学和生物学的几个领域产生影响。PI将把部分研究成果纳入乔治梅森大学（George Mason University）的课程和学生项目，并向当地高中学生作报告，作为其推广工作的一部分。

NONTECHNICAL SUMMARYThis award supports theoretical and computational research and education on the properties of materials interfaces. Interfaces are ubiquitous and important in many natural phenomena, e.g. in how materials break and deform, and consequently play important roles in many areas of science and technology. The goal of this project is to advance fundamental understanding of the effects of temperature, chemical composition, interface shape and other factors on interface properties. The main approach to achieving this goal is close integration of general theoretical analysis with computer simulations.The research will provide a theoretical framework for the development of new models for interface properties and interface-controlled processes, and will provide new capabilities for their computational prediction. This improved understanding will enhance our ability to control materials properties for many classes of technologically important materials, including many varieties of alloys and nanowires. Furthermore, it will strengthen the theoretical foundations for the design of new nanostructured materials. The project is expected to have impact on several areas of materials science, physics, chemistry, and biology. The PI will incorporate some of the research results into courses and student projects at George Mason University, and in presentations given to students of local high-schools as part of his outreach efforts.TECHNICAL SUMMARYThis award supports theoretical and computational research and education on the thermodynamic properties of materials interfaces. Interfaces are ubiquitous and important in many natural phenomena, such as materials fracture and deformation, and consequently play important roles in many areas of science and technology. The goal of this project is to advance the fundamental understanding of interface thermodynamics and investigate the effects of temperature, chemical composition, interface curvature and other factors on interface properties.Four research directions will be pursued in this project: (1) investigation of structural phase transformations in metallic grain boundaries (GBs), including the construction of GB phase diagrams; (2) investigation of structure and properties of alloy GBs at high temperatures approaching the melting point; (3) analysis of equilibrium thermal fluctuations of interface properties and development of efficient methods for computational prediction of such properties; and (4) development of thermodynamics of strongly curved interfaces, including extensions of the existing theory to non-spherical interfaces and incorporation of quadratic and higher-order effects in curvature. The atomistic simulations will utilize molecular dynamics, Monte Carlo, and other techniques.The research will provide a theoretical framework for the development of new models of phase and interface stability, phase nucleation, and other interface-controlled processes. The project will lead to a better fundamental understanding of interface thermodynamics and will provide new capabilities for its computational prediction. The improved understanding of interface thermodynamics will enhance our ability to control precipitation and coarsening in structural materials such as superalloys, solidification microstructures in cast alloys, nanowire growth, and reactive wetting.The project is expected to have impact on several areas of materials science, physics, chemistry, and biology. The PI will incorporate some of the research results into courses and student projects at George Mason University, and in presentations given to students of local high-schools as part of his outreach efforts.