| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
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| Symposium
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Atomistic Simulations Linked to Experiments to Understand Mechanical Behavior: A MPMD Symposium in Honor of Professor Diana Farkas
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| Presentation Title |
Understanding the Fundamental Fracture Behavior in NbMoTaW and NbTaTiHf |
| Author(s) |
Wenqing Wang, Diana Farkas, Robert Ritchie, Mark Asta |
| On-Site Speaker (Planned) |
Wenqing Wang |
| Abstract Scope |
Refractory high entropy alloys (RHEAs) are renowned for their high strength and compressive ductility at elevated temperatures, yet their practical application is often limited by inadequate tensile ductility at ambient temperature. Recently, a novel RHEA, NbTaTiHf, has demonstrated exceptional tensile ductility and fracture toughness from cryogenic to room temperatures. In this study, we investigate and compare two bcc RHEAs, NbMoTaW and NbTaTiHf, with markedly different ductility and fracture toughness behaviors. At room temperature, NbMoTaW fractures at approximately 5% tensile strain through a combination of intergranular and transgranular modes, whereas NbTaTiHf exhibits fracture at over 30% tensile strain via ductile microvoid coalescence. To elucidate the underlying differences between these alloys, MD fracture simulations are conducted on single-crystal and polycrystalline samples of NbMoTaW and NbTaTiHf under mode I loading. Crack tip behavior is analyzed using a Rice-Thompson based criterion, revealing results consistent with experimentally observed ductility discrepancies between the two alloys. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, High-Entropy Alloys, Mechanical Properties |