About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Role of Oxygen in Phase Stability and Mechanical Behavior of the bcc HfNbTaTiZr High-Entropy Alloy During Aging |
| Author(s) |
Yujun Zhao, Maik Rajkowski, Yilun Gong, Alexander Kauffmann, Tong Li, Guillaume Laplanche, Jean-Philippe Couzinié, Loïc Perrière |
| On-Site Speaker (Planned) |
Yujun Zhao |
| Abstract Scope |
This work explores the effects of oxygen on the phase stability and
mechanical behavior of the body-centered cubic (bcc) HfNbTaTiZr
high-entropy alloy. Microstructural evolutions in HfNbTaTiZr without
and with 3 at.% O (HfNbTaTiZr-3O) during aging at 500 °C were revealed by
transmission electron microscopy and atom probe tomography. In
HfNbTaTiZr, Zr-Hf-rich body-centered tetragonal (bct) channels (~2.7
nm in thickness) form along <001>bcc at early stages.
Meanwhile, a Zr-Hf-rich hexagonal closed-packed (hcp) phase (~3.6 nm)
and a Ti-rich ω phase (~11.1 nm) form at the channel nodes. As aging
proceeds, the ω phase disappears, and the bct phase transforms into a
distorted hexagonal phase. In HfNbTaTiZr-3O, the finer bct channels
(~2.1 nm) are stabilized by oxygen, hindering the bct-to-hcp
transformation. After long-term aging, the ω phase persists accompanied
by oxygen partitioning from the hcp phase. Tensile tests and
micro-mechanical tests show the nanometer-sized phases strengthen
the grain interiors of the alloys. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Mechanical Properties, |