About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
|
High Entropy Alloys VIII
|
Presentation Title |
J-95: Generalized Planar Fault Energies and Twinning in NbMoTaW BCC High Entropy Alloy: A First-principles Study |
Author(s) |
Abu Anand, Chandra Veer Singh |
On-Site Speaker (Planned) |
Abu Anand |
Abstract Scope |
High entropy alloys of refractory elements have reported exhibiting superior mechanical properties while having low-density. In this work, we investigate the generalised fault energies of the BCC High Entropy Alloy system NbMoTaW using Density Functional Theory. Energy landscapes for twinning and slipping were calculated for NbMoTaW and compared with the component elements. The stacking fault and planar fault energy values for the HEA is lower than that of all component elements. Twinnability ratio (γ_TBM/∆us) was found to be 0.13 suggesting extensive deformation twinning in the HEA system. Origin of low fault energies was investigated using Integrated Crystal Orbit Hamilton Population (ICOHP). Except for W-Mo, W-Ta, interactions in NbMoTaW was found to be as weak as the Nb-Nb pure metal interactions which explain the reduced fault energies. Twin formation is less likely to happen near Tungsten rich portions of the alloy due to strong ICOHP interactions. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume; Planned: Supplemental Proceedings volume |