About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
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Algorithm Development in Materials Science and Engineering
|
Presentation Title |
Coarse-graining Techniques for Migration of Solutes around Defects |
Author(s) |
Xiaowang Zhou, Christian Nowak, Catalin Dan Spataru, Michael Foster, Kevin Chu, Ryan Sills |
On-Site Speaker (Planned) |
Xiaowang Zhou |
Abstract Scope |
Hydrogen Cottrell atmosphere prescribes elevated hydrogen concentrations near dislocations which can contribute to hydrogen embrittlement. Traditional atomistic simulations of Cottrell atmosphere can only be achieved using Monte Carlo methods where smooth concentration profiles are averaged over millions or more configurations. These methods preclude the effects of important phenomena including dislocation thermal vibration, solute-solute dynamic interaction, and dislocation migration under applied stresses. Molecular dynamics methods do not have these limitations, but they deal only with one configuration which cannot yield smooth concentration profiles. Here we demonstrate that for a fast diffusion solute like hydrogen, time and ensemble averaged molecular dynamics methods also enable averages of millions or more distinct configurations, resulting in smooth calculations of Cottrell atmosphere. We have performed such molecular dynamics simulations to study hydrogen Cottrell atmospheres around edge dislocations in aluminum and stainless steel alloys revealing important insights of Cottrell atmosphere formation not known in the past. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Modeling and Simulation, Aluminum |