|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Advanced Characterization Techniques for Quantifying and Modeling Deformation
||Investigation of Grain Size Effects on Cyclic Deformation and Twinning in Magnesium Alloys by High Energy X-ray Diffraction
||Duncan A. Greeley, Mohammadreza Yaghoobi, Katherine Shanks, Darren Pagan, Veera Sundararaghavan, John Allison
|On-Site Speaker (Planned)
||Duncan A. Greeley
The grain size distribution in polycrystalline materials has a significant impact on yield and flow stress during deformation. Plastic cyclic deformation in magnesium alloys is accommodated by a mix of dislocation slip and twinning depending on sample texture and loading conditions and understanding the impact of grain size on activity of individual deformation modes is important for accurately modeling fatigue behavior. Compression-tension cyclic deformation was characterized in Mg-4wt.%Al and Mg-2.4wt.%Nd binary alloys under multiple grain size conditions using High Energy X-Ray Diffraction Microscopy (HEDM) at the Cornell High Energy Synchrotron Source (CHESS). Grain-scale cyclic twinning and detwinning, basal, prismatic, and pyramidal II <c+a> slip mode critical resolved shear strength, and the evolution of sample texture were tracked using far-field HEDM and near-field HEDM. The impact of grain size on the evolution of deformation during cyclic displacement was investigated and simulated with the PRISMS-Plasticity crystal plasticity finite element software.