| About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Behavior and Degradation of Advanced Nuclear Fuel and Structural Materials
|
| Presentation Title |
Hydrogen Accommodation in the TiZrNbHfTa High Entropy Alloy |
| Author(s) |
Christopher Moore, Jack Wilson, Michael Rushton, Jack Astbury, Simon Middleburgh |
| On-Site Speaker (Planned) |
Christopher Moore |
| Abstract Scope |
The TiZrNbHfTa high entropy alloy (HEA), and its hydrides (TiZrNbHfTaH0.4-1.6) have been modelled as special quasi-random structures, with density functional theory calculations to analyse key thermodynamic processes such as vacancy formation energies and hydrogen absorption. A calculated Schottky energy of 1.43 eV is lower than expected compared to other simple metallic systems. Investigations reveal the formation of split vacancy like defects which reduce vacancy formation energy barriers but may also allow for energetically favourable recombination after radiation damage events. Hydrogen interstitials preferentially adopt tetrahedral sites at both low and high hydrogen concentrations and were also found to promote vacancy formation within the HEA. Interstitials positioned around vacancies display a change in site preference to octahedral site occupation. Hydride decomposition was modelled and a release of hydrogen over a range of temperatures was predicted, in agreement with recent experimental results, contrary to that seen in simple metal hydride systems. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Modeling and Simulation, Computational Materials Science & Engineering |