| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Computational Thermodynamics and Kinetics
|
| Presentation Title |
Mechanistic understanding of vacancy formation energies in FCC HEAs from DFT calculations |
| Author(s) |
Nathan Linton, Dilpuneet S. Aidhy |
| On-Site Speaker (Planned) |
Dilpuneet S. Aidhy |
| Abstract Scope |
Due to chemical and lattice symmetries, pure metals have single values vacancy formation energy (VFE). However, concentrated alloys, such as high entropy alloys (HEAs), have a range of VFEs due to diverse nearest neighbor (NN) environments. While previous studies have illustrated a correlation between NN chemistry and VFE, here, using density functional theory (DFT) calculations, we show that atomic volume and electronegativity have a significant effect. Specifically, larger atomic volume increases VFE. In addition, charge gain due to higher electronegativity also increases VFE. We find that such mechanisms can lead to large VFE variations, at times over 1 eV. The study is performed in model FCC alloys including binary Ni-Cu, Cu-Au, Ag-Au and ternary Ni-Cu-Au. We show that the fundamental principles observed in binary alloys translate into ternary alloys. These observations would be helpful in the design and development of concentrated alloys for high temperature applications. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, High-Entropy Alloys, Other |