About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
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Symposium
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Advances in Multi-Principal Element Alloys III: Mechanical Behavior
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Presentation Title |
Fracture of Refractory High Entropy Alloys in Extreme Temperature Environments |
Author(s) |
David Cook, Punit Kumar, Calvin Belcher, Madelyn Payne, Wenqing Wang, Pedro Borges, Flynn Walsh, Mingwei Zhang, Andrew Minor, Mark Asta, Diran Apelian, Enrique Lavernia, Robert Ritchie |
On-Site Speaker (Planned) |
David Cook |
Abstract Scope |
Body-centered cubic (bcc) refractory high-entropy alloys (RHEAs) represent a new paradigm for high temperature structural materials due to their ability to retain high compressive strengths at elevated temperatures. However, when their fracture properties are considered, this class of materials occupies two extremes. For example, the NbMoTaW alloy exhibits fracture toughness and tensile ductility below 10 MPa√m and 0.15% from 298–1473 K, respectively. These low values are attributed to brittle cleavage at ambient temperatures, and intergranular fracture at elevated temperatures. Conversely, group IV enriched RHEAs show tensile ductility and rising R-curve behavior not just at high temperatures but also cryogenic temperatures. At these low temperatures, the material fractures by microvoid coalescence—remarkable for bcc alloys that suffer from ductile-to-brittle transitions. In this talk, the mechanical behavior and microstructural origin of the damage tolerance of bcc RHEAs will be extensively discussed. |
Proceedings Inclusion? |
Planned: |
Keywords |
High-Entropy Alloys, High-Temperature Materials, Mechanical Properties |