Defect Interactions in Solids: Impact on Microstructure and Materials Properties

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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.