About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Thermodynamics and Kinetics
|
Presentation Title |
A First-principles Analysis of the Temperature Dependence of Stacking Fault Energies and Cross-slip Barrier in Mg and Its Alloys |
Author(s) |
Julian L. Brodie, Maryam Ghazisaeidi |
On-Site Speaker (Planned) |
Julian L. Brodie |
Abstract Scope |
Magnesium is interesting due to its high strength, low density, recyclability, and applications in automotive and aerospace industries. However, Mg has poor room temperature ductility due to its hexagonal-closed-packed structure which results in an insufficient number of available slip systems at low temperatures. However, recent theoretical studies show improving the room temperature ductility of Mg may be accomplished by decreasing the cross-slip energy barrier between the pyramidal I and II planes in Mg via dilute solute additions. As the calculations were performed at 0K, calculations at higher temperatures are needed. We use Density Functional Theory to compute the stacking fault energy on relevant slip planes in Mg and its alloys. We then use phonon information extracted using Density Functional Perturbation Theory and the Quasiharmonic Approximation to determine the temperature dependence of the stacking faults. Finally, we determine the cross-slip energy barrier as a function of temperature for the Mg alloys. |
Proceedings Inclusion? |
Planned: |
Keywords |
Magnesium, Computational Materials Science & Engineering, |