| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Multi-Principal Element Alloys IV: Mechanical Behavior
|
| Presentation Title |
First-Principles Study of the Effect of Si Doping on the Local Chemical Ordering, Secondary Phase Formation, and Stacking-Fault Energy of the CoCrNi MEA |
| Author(s) |
Chin-Lung Kuo |
| On-Site Speaker (Planned) |
Chin-Lung Kuo |
| Abstract Scope |
We employed first-principles calculations to investigate the effect of Si-doping on the local chemical ordering, secondary phase formation, and stacking-fault energy of the CoCrNi MEA. Our calculations first revealed the presence of local-chemical ordering in CoCrNi MEA, where Co-Cr and Ni-Cr tend to aggregate while Cr-Cr tends to separate. Upon the addition of Si to the CoCrNi MEA, Ni/Co and Si tend to form Ni3Si/Ni3Co(L12) precipitates, resulting in the formation of the Cr-rich region in the material matrix. As the number of Ni3Si/Ni3Co precipitates increases, BCC and σ phases are likely to nucleate within the Cr-rich region. Furthermore, the stacking-fault energy of the SixCoCrNi MEA was found to increase with the Si content, while the barrier for deformation twinning decreased. Considering the formation of Ni3Si/Ni3Co(L12) precipitates, the stacking-fault energy of the remaining region can be substantially reduced. These reasons may contribute to the improved mechanical strength of CoCrNi MEA. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, High-Entropy Alloys, Modeling and Simulation |