| About this Abstract |
| Meeting |
TMS Specialty Congress 2024
|
| Symposium
|
Accelerating Discovery for Mechanical Behavior of Materials 2024
|
| Presentation Title |
Fracture of Refractory High Entropy Alloys in Extreme Temperature Environments |
| Author(s) |
David Cook, Punit Kumar, Calvin Belcher, Madelyn Payne, Pedro Borges, Wenqing Wang, Flynn Walsh, Mingwei Zhang, Mark Asta, Andrew Minor, Enrique Lavernia, Diran Apelian, Robert Ritchie |
| On-Site Speaker (Planned) |
David Cook |
| Abstract Scope |
Body-centered cubic (bcc) refractory high-entropy alloys (RHEAs) inhabit the two extremes of the strength-toughness trade-off across extreme temperature environments. While the group V-VI alloys, represented by the model NbMoTaW system, have high compressive strengths at high temperatures, they suffer from extremely poor tensile ductility and fracture toughness. On the other hand, the group IV-V alloys can exhibit significant tensile ductility, and high ambient temperature fracture toughness, but lose strength and ductility at higher temperatures. In this talk, a novel RHEA that beats the strength-toughness trade-off across extreme temperature regimes is discussed. This material exhibits high temperature strength, and high fracture toughness characterized by rising R-curve behavior, even in the cryogenic regime. These remarkable properties can be attributed to deformation mechanisms that cause strain softening, which runs counter to long-held notions that fracture toughness of metals is derived from mechanisms that prolong uniform ductility and delay plastic instability through strain hardening. |
| Proceedings Inclusion? |
Definite: Other |