|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Seeing is Believing -- Understanding Environmental Degradation and Mechanical Response Using Advanced Characterization Techniques: An SMD Symposium in Honor of Ian M. Robertson
||Modeling Grain Boundary Mediated Plasticity with Massively Parallel Atomistic Simulations
||Timofey Frolov, Nicolas Bertin, Tomas Oppelstrup
|On-Site Speaker (Planned)
The plasticity of polycrystals is greatly influenced by grain boundaries (GBs), interfaces that can act as obstacles for dislocation motion. The resulting strengthening effect is described by the well-known Hall-Petch relation. A different strengthening mechanism referred to as dislocation starvation has also been demonstrated for small single crystals, where the bulk material is essentially dislocation-free and the plasticity is accommodated by dislocations nucleating at free surfaces. We perform large-scale MD and DD simulations of bicrystal deformation to investigate the dynamic competition between dislocation multiplication in the bulk and their nucleation at GBs. We identify grain size and deformation rate regimes where the plasticity and strength are governed by the nucleation of dislocations at GBs. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
||Computational Materials Science & Engineering, Mechanical Properties, Modeling and Simulation