Defect Interactions in Solids: Impact on Microstructure and Materials Properties

这个奖项是对先前的NSF青年研究者奖的更新。目前的拨款用于理论建模，以评估点和线缺陷之间的相互作用对缺陷微结构和相关材料特性的影响。晶体缺陷，当大量存在时，可以极大地改变材料的热性能和机械性能；定量了解控制缺陷结构、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。所提出的工作的重点将放在相互作用的空位、间隙和位错的热力学和动力学的中尺度和连续体描述上。这些系综的平衡和亚稳性质可以用统计力学方法处理，并使用粗粒化程序将其与相应的宏观缺陷密度联系起来。几个互补的计算和分析技术将在这个项目中使用，包括动力学蒙特卡罗模拟和平均场理论模拟。该奖项是先前NSF青年研究者奖的更新。目前的拨款用于理论建模，以评估点和线缺陷之间的相互作用对缺陷微结构和相关材料特性的影响。晶体缺陷，当大量存在时，可以极大地改变材料的热性能和机械性能；定量了解控制缺陷结构、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。所提出的工作的重点将放在相互作用的空位、间隙和位错的热力学和动力学的中尺度和连续体描述上。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.