Multiscale modeling of microstructures in nuclear structural materials for extreme environment
Abstract: Degradation of nuclear structural materials by radiation damage poses a serious concern to the reliability and safety of nuclear reactors. Predicting the rate processes of radiation-induced chemical and structural instability is essential for the lifetime extension of current nuclear reactors, as well as the development of radiation-tolerant materials for advanced nuclear energy technologies. Modeling radiation effects in structural alloys is challenging, as various microstructural events and phenomena produced by bombardment of energetic particles are over wide ranges of time and length scales. Multiscale and integrated approaches of microstructural modeling are thus critically required. The presentation will feature an integrated modeling strategy to study mesoscale evolution of irradiated microstructure. Examples include simulation studies of the irradiation flux effect on precipitation in iron-chromium model alloys and radiation-induced segregation in low-alloyed steels. I will also discuss the challenges and potential ways to predict and understand alloy properties involving chemical complexity, including the use of lower-length scale first-principles calculations and cluster approach to explore the hidden role of excess point defects in alloy phase stability.
Bio: Dr. Jia-Hong Ke is a Staff Scientist in the Computational Microstructure Science Group as a part of the Computational Mechanics and Materials Department at Idaho National Laboratory (INL). Before joining INL in 2020, he was a staff faculty researcher at Oregon State University and a postdoctoral researcher at University of Wisconsin-Madison. He has over ten years of experience in multiscale modeling – from atomic (density functional theory and cluster expansion) to mesoscale (cluster dynamics rate theories and phase field) modeling of alloys. Dr. Ke’s primary areas of expertise are in phase stability and impurity-defect interaction in extreme environment. He has been working on the simulations of radiation-induced precipitation and flux effects in iron-chromium model alloys, solute segregation and defect clustering in ferritic-martensitic and reactor pressure vessel steels, short-range and long-range ordering in nickel-based alloys, as well as fission product transport in fuel particles. His work currently supports US DOE’s Nuclear Energy Advanced Modeling and Simulation and Advanced Materials and Manufacturing Technologies programs. He is a member in the Nuclear Materials committee in TMS.