|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Computational Design and Simulation of Materials (CDSM 2018): Meso/Macroscale Simulations
||Examination of Precipitate Composition, Morphology, and Interactions in Mg-RE Alloys Using Phase Field Modeling
||Stephen DeWitt, Katsuyo Thornton, John E Allison
|On-Site Speaker (Planned)
Magnesium-rare earth (Mg-RE) alloys are of interest as structural materials due to their high specific strength, largely attributed to β''' precipitates that form during aging. We present phase field simulations of β''' precipitates in two prototypical Mg-RE alloys, Mg-Nd and Mg-Y. First, isolated precipitates are examined. Consistent with observations, differing composition dependence of the misfit strain causes the simulated Mg-Nd precipitates, but not Mg-Y precipitates, to exhibit elevated RE composition. Also consistent with observations, the simulated Mg-Nd precipitates are lenticular while Mg-Y precipitates are rod-like with a square cross-section. Taking parametric uncertainty into account, the predicted precipitate dimensions are quantitatively consistent with experiments. Second, the capability to predict the precipitate microstructure of an Mg-RE alloy is demonstrated by a concurrent nucleation and growth simulation in Mg-Y. The evolution of precipitate number density during aging and the effect of precipitate interactions on the shape distribution are discussed and compared to observations.
||Planned: Supplemental Proceedings volume