Defect Interactions in Solids: Impact on Microstructure and Materials Properties

这一奖项是对之前NSF青年调查员奖的续展。目前的资助是用于理论建模，以评估点缺陷和线缺陷之间的相互作用对缺陷微结构和相关材料性能的影响。当晶体缺陷大量存在时，会极大地改变材料的热和机械性能；定量地了解控制缺陷结构、迁移率和化学环境的因素对于解释观察到的现象和设计具有所需特性的新材料至关重要。拟议工作的重点将放在相互作用的空位、间隙和位错的系综的热力学和动力学的介观和连续描述上。这些系综的平衡和亚稳态性质可以用统计力学方法处理，并通过粗粒化过程与相应的宏观缺陷密度联系起来。在这个项目中将使用几种互补的计算和分析技术，包括动力学蒙特卡罗模拟和平均场理论模拟。这一奖项是对之前NSF青年研究员奖的续展。目前的资助是用于理论建模，以评估点缺陷和线缺陷之间的相互作用对缺陷微结构和相关材料性能的影响。当晶体缺陷大量存在时，会极大地改变材料的热和机械性能；定量地了解控制缺陷结构、迁移率和化学环境的因素对于解释观察到的现象和设计具有所需特性的新材料至关重要。拟议工作的重点将放在相互作用的空位、间隙和位错的系综的热力学和动力学的介观和连续描述上。冶金过程的模拟结果可以纳入材料科学计算方法的二年级课程。

9975384RickmanThis award is a renewal of a prior NSF Young Investigator award. The current grant is for theoretical modeling to assess the impact of mutual interactions among point and line defects on defect microstructures and associated materials properties. Crystalline defects, when present in large quantities, can dramatically alter the thermal and mechanical properties of materials; a quantitative understanding of the factors governing defect structure, mobility, and chemical environment is essential to explain observed phenomena and to engineer new materials with desired characteristics. The focus of the proposed work will be on mesoscale and continuum descriptions of the thermodynamics and kinetics of ensembles of mutually interacting vacancies, interstitials, and dislocations. Equilibrium and metastable properties of these ensembles can be treated using statistical mechanics methods and linked with corresponding macroscopic defect densities using a coarse-graining procedure. Several complementary computational and analytical techniques will be used in this project, including kinetic Monte Carlo simulations and mean-field theory simulations.This award is a renewal of a prior NSF Young Investigator award. The current grant is for theoretical modeling to assess the impact of mutual interactions among point and line defects on defect microstructures and associated materials properties. Crystalline defects, when present in large quantities, can dramatically alter the thermal and mechanical properties of materials; a quantitative understanding of the factors governing defect structure, mobility, and chemical environment is essential to explain observed phenomena and to engineer new materials with desired characteristics. The focus of the proposed work will be on mesoscale and continuum descriptions of the thermodynamics and kinetics of ensembles of mutually interacting vacancies, interstitials, and dislocations. Simulation results for metallurgical processes can be incorporated into a sophomore-level course on computational methods in materials science.