About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
2026 Graduate Student Poster Contest
|
| Presentation Title |
SPG-17: Impact of Chemical Short-Range Order on Planar-Fault and Dislocation Properties in NiCoV Alloys |
| Author(s) |
Dalia M. Sayed Ahmed, Mia Jin, Yang Yang, Yongwen Sun |
| On-Site Speaker (Planned) |
Dalia M. Sayed Ahmed |
| Abstract Scope |
The Ni–Co–V medium-entropy alloy exhibits exceptional strength and ductility, often attributed to pronounced chemical short-range order (CSRO) driven by Ni–V and Co–V affinity. However, how CSRO governs stacking-fault energetics and dislocation motion remains unresolved. Using atomistic simulations with a first-principles-trained interatomic potential, we examine the effects of increasing CSRO on stacking-fault energy and dislocation-mediated plasticity. As CSRO intensifies, the average intrinsic stacking-fault energy increases from 25 to 95 mJ/m², while the mean critical resolved shear stress rises from 340.9 ± 23.0 to 521.3 ± 20.9 MPa. Increasing order also reduces partial-dislocation separation and increases resistance to glide. Ni–V- and Co–V-rich CSRO clusters along the glide plane produce dislocation bowing, kinking, and transient pinning, revealing spatially heterogeneous chemical strengthening. These results quantitatively link local chemical order to stacking-fault energetics and dislocation mobility in Ni–Co–V alloys. |