Computation of Grain Boundary Energy Landscapes as a Tool for Grain Boundary Engineering

晶界是金属和陶瓷中的缺陷，通常控制腐蚀和开裂等失效机制。然而，在一个给定的材料样品中可以发现大量不同的晶界类型。通过一种称为晶界工程的过程来控制材料中存在的晶界类型，可以显著增强材料的性能，包括抗腐蚀和抗裂性。该项目的目的是通过研究不同类型晶界的特性来推进晶界工程领域，以确定哪种晶界在防止或导致材料失效方面最重要。为了实现这一点，使用一种称为激活松弛技术的计算方法研究了各种不同类型的晶界。这种方法提供了关于晶界动力学特性的基本信息，这与材料降解和破坏机制有着内在的联系。本工作的研究成果将推动晶界工程领域的发展。告诉材料设计师材料结构中最关键的缺陷是什么，使他们能够专注于消除这些关键缺陷，从而延长各种工程材料的使用寿命。因此，微观结构水平的材料设计工具箱将大大增加，在减少材料失效，提高产品可靠性，从而减少材料使用方面具有社会效益。该项目还侧重于培养博士级专家和学士级从业人员使用最新的微结构设计工具。结合对工业问题的研究，这些新培训的学生准备将研究成果带入实地并在先进材料技术中实施。

Grain boundaries are defects in metals and ceramics that often control failure mechanisms such as corrosion and cracking. However, a vast number of different grain boundary types are found in a given material specimen. By controlling the types of grain boundaries present in a material through a process called grain boundary engineering, dramatic enhancements in materials performance, including corrosion and cracking resistance, can be achieved. The aim of this project is to advance the field of grain boundary engineering by investigating the properties of different types of grain boundaries in order to determine which grain boundaries are most important in preventing or causing materials failure. To accomplish this, a variety of different types of grain boundaries are investigated using a computational method called the activation-relaxation technique. This method provides essential information regarding the kinetic properties of grain boundaries, which are inherently related to the mechanisms of material degradation and failure. The research results produced in this work will advance the field of grain boundary engineering?telling materials designers what the most critical defects in a material structure are allows them to focus on removing those critical defects, thereby extending the lifetime of a variety of engineering materials. The toolbox for materials design at the microstructural level will thus be greatly augmented, with societal benefits in reducing materials failures, enhancing product reliability, and thereby reducing materials usage. The project also focuses on the training of Ph.D.-level experts and B.S.-level practitioners in the newest tools of microstructure design. Combined with significant exposure of the research to industrial concerns, these newly-trained students are poised to carry the research results into the field and effect their implementation in advanced materials technologies.