| About this Abstract |
| Meeting |
2023 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Multi-Principal Element Alloys II
|
| Presentation Title |
Understanding the Short-range Ordering and Dislocation Behavior in BCC Refractory High Entropy Alloys |
| Author(s) |
Shuai Chen, Zachary Aitken, Subrahmanyam Pattamatta, Zhaoxuan Wu, Zhi-Gen Yu, David Srolovitz, Peter Liaw, Yong-Wei Zhang |
| On-Site Speaker (Planned) |
Yong-Wei Zhang |
| Abstract Scope |
Despite intense research efforts, the fundamental mechanisms behind some remarkable phenomena of dislocations in BCC refractory high entropy alloys (RHEAs) remain unclear. Here, we investigate the underlying driving force for the short-range ordering (SRO) in a BCC MoTaTiWZr RHEA containing grain boundaries and the effects of SRO on the dislocation nucleation and propagation and resulting mechanical properties using a combination of the Monte Carlo method, molecular dynamic simulation, and density-functional theory calculation. Our results show that this RHEA is energetically favorable to undergo SRO driven the disparity and exclusivity of chemical affinity of its constituent elements. It is found that SROs enhance the energy barriers for both edge and screw dislocation motions and make the mobility of edge dislocations comparable to or even lower than screw dislocations, contributing to the unique dominance of edge dislocations in the BCC RHEA. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Computational Materials Science & Engineering, High-Temperature Materials |