| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Materials for Sustainable Hydrogen Energy
|
| Presentation Title |
Decomposition and Decelerated Grain Growth of the Nanostructured High Entropy Alloy TiVZrNbHf under Hydrogen |
| Author(s) |
Lukas Schweiger, Felix Roemer, Goekhan Gizer, Michael Burtscher, Daniel Kiener, Claudio Pistidda, Alexander Schoekel, Florian Spieckermann, Juergen Eckert |
| On-Site Speaker (Planned) |
Lukas Schweiger |
| Abstract Scope |
This study examines the potential of nanostructuring the high-entropy alloy (HEA) TiVZrNbHf by high-pressure torsion to enhance its hydrogen absorption properties. Microstructural analysis after processing shows that a single-phase nanocrystalline structure was obtained despite shear band development. Given the metastable character of many high entropy alloys, the thermal stability of the alloy under both vacuum and hydrogen was investigated. In-situ X-ray diffraction during hydrogen absorption at 500 °C demonstrated the inherent metastability of TiVZrNbHf, involving the decomposition into bcc, hcp, and C14 Laves phases under both conditions. Despite this decomposition, the material retained its nanocrystalline structure under hydrogen, presumably due to hydride formation, while significant grain growth occurred under vacuum. These findings point towards decelerated grain growth under hydrogen, contribute to a better understanding of this HEA and suggest an approach for engineering such alloys for enhanced stability and performance, particularly in solid-state hydrogen storage applications. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Phase Transformations, Energy Conversion and Storage |