About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Advances in Refractory High Entropy Alloys and Ceramics
|
| Presentation Title |
On the Strength and Ductility of Refractory High Entropy Alloys |
| Author(s) |
Mingwei Zhang, Jacob Pustelnik, Tamanna Zakia, Ayeman Nahin, Michael Lau |
| On-Site Speaker (Planned) |
Mingwei Zhang |
| Abstract Scope |
The development of advanced alloy systems capable of operating beyond the temperature limits of Ni-based superalloys is crucial for space exploration, energy sustainability, and defense applications. Refractory High Entropy Alloys (RHEAs) are promising candidates due to their high melting points and strength at elevated temperatures. However, challenges remain in achieving a balance between room-temperature tensile ductility and high-temperature strength. We show that bulk and grain boundary phase decomposition, grain boundary oxide formation, and significant grain coarsening due to homogenization are the critical mechanisms to compromise tensile ductility in intrinsically ductile RHEAs. On the other hand, current ductile NbTaTi-based RHEAs show insufficient strength due to significant softening from screw dislocation glide-controlled deformation at elevated temperatures. These limitations call for the development of particle-strengthened, edge dislocation glide-controlled RHEAs to achieve a good combination of phase stability, tensile ductility, creep strength, and recrystallization resistance. |