About this Abstract |
Meeting |
2025 TMS Annual Meeting & Exhibition
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Symposium
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Advanced Characterization Techniques for Quantifying and Modeling Deformation
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Presentation Title |
An Integrated Experimental - PRISMS-Plasticity Study of Geometrically Necessary Dislocation Density Development in Mg Alloys. |
Author(s) |
Michael Pilipchuk, Tracy Berman, John Allison, Veera Sundararaghavan |
On-Site Speaker (Planned) |
Michael Pilipchuk |
Abstract Scope |
Geometrically Necessary Dislocations (GNDs) form in polycrystals to accommodate deformation while maintaining compatibility in the presence of a strain gradient. These dislocations pile up on grain boundaries due to the energy barrier required to transit to a differently oriented grain. As their density increases, dislocation mobility decreases, leading to backstress and hardening. Various approaches have been proposed to model the formation of GNDs through incompatibility. For this work, the curl of the plastic deformation gradient is used to determine the Nye tensor and, in turn, the GND density by L2 minimization. This approach is built into PRISMS-Plasticity, an advanced open-source crystal plasticity finite element code and validated experimentally. The computational work used a ZX30 (Mg–3Zn–0.1Ca by wt%) microstructure created in Dream3D and modeled deformation in PRISMS-Plasticity to determine the deformation gradients. The results are compared against GND densities calculated from electron backscatter diffraction maps of ZX30 deformed at 200ºC in plane strain compression to 4%, 8%, and 17% plastic strain. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Modeling and Simulation, Characterization |