About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
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| Symposium
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Advances in Multi-Principal Element Alloys V: Mechanical Behavior
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| Presentation Title |
Exploring Phase Stability and Deformation Mechanisms in Refractory Compositionally Complex Alloys Across the Compositional Boundary Between Mo–W-Rich and Senkov-Type Alloys |
| Author(s) |
Carla Joyce C. Nocheseda, Eric A Lass, Benjamin Wing, Stephen Puplumpu, Vivek Chawla, Andrew Wood, Dayakar Penumadu |
| On-Site Speaker (Planned) |
Carla Joyce C. Nocheseda |
| Abstract Scope |
Refractory Compositionally Complex Alloys (R-CCAs) present a trade-off between room-temperature ductility and high-temperature strength. Alloys in the Senkov family (e.g., Hf–Zr–Ti–Nb–Ta based) are ductile but soften at elevated temperatures, while Mo- and W-containing BCC alloys exhibit high-temperature strength but tend to be brittle. This study investigates alloys in the in-between compositional regime—such as Nb40Ta25Ti15, MoNbTi, and NbTaTi to explore pathways toward balancing these opposing traits. We use the free energy difference between BCC and HCP phases ΔG (BCC→HCP) as a thermodynamic indicator to interpret how phase stability may relate to deformation behavior. These alloys mostly fall within the positive ΔG (BCC→HCP) regime, approaching the Mo- and W-rich hard BCC alloy space, known for high-temperature strength but poor room-temperature ductility. Ongoing microstructural analysis explores whether deformation in this regime is governed by dislocation mode shifts rather than phase transformation, offering new insight into mechanical behavior across alloy classes. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, High-Temperature Materials, Nuclear Materials |