About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
|
High Entropy Alloys VIII
|
Presentation Title |
Simulations and Modeling of the High Temperature Yield Behavior of Chemically Complex Concentrated BCC Alloys |
Author(s) |
Satish I. Rao, Brahim Akdim, Edwin Antillon, Christopher Woodward, Oleg Senkov |
On-Site Speaker (Planned) |
Satish I. Rao |
Abstract Scope |
Atomistic simulations of the core structure and mobility of ½[111] screw, edge and mixed dislocations in multicomponent chemically complex BCC alloys using Johnson-Zhou potentials, are presented. The core structure and its variations obtained for screw dislocations in NbTiZr using the Johnson-Zhou potentials are compared with first-principles calculation results and found to be in good agreement. The screw dislocation is shown to leave behind interstitial and vacancy dipole debris during its motion in these alloys. Average solute-dislocation core interaction energies are used to determine the critical stress for the motion of screw dislocations as a function of temperature using the Suzuki model of kink migration controlled mobility developed for concentrated BCC random alloys. The effect of diffusion at high temperatures on the predicted yield behavior is discussed. Finally, the edge and mixed dislocation to screw dislocation mobility ratio in these alloys are shown to be low, ~ 2 at 5K. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume; Planned: Supplemental Proceedings volume |