About this Abstract |
| Meeting |
TMS Specialty Congress 2026
|
| Symposium
|
4th World Congress on High Entropy Alloys (HEA 2026)
|
| Presentation Title |
Role of Short-Range Order and Strain Rate on Dislocation-Mediated Plasticity in CrCoNi Medium-Entropy Alloys |
| Author(s) |
Fatemeh Ghajari, Mobin Vandadi, Nima Rahbar |
| On-Site Speaker (Planned) |
Fatemeh Ghajari |
| Abstract Scope |
HEAs/MEAs exhibit exceptional mechanical properties arising from their chemical complexity and heterogeneous atomic environments. This study investigates the deformation behavior of a CrCoNi medium-entropy alloy using a multiscale approach combining micropillar compression, molecular dynamics, and discrete dislocation dynamics simulations. Micropillar tests performed over a range of strain rates reveal a transition from planar slip dominated by Shockley partial dislocations at low strains to pronounced slip band formation and twinning at higher strain rates. Transmission electron microscopy shows spatially heterogeneous dislocation structures linked to local variations in stacking fault energy. Atomistic simulations demonstrate that chemical short-range order (SRO) modulates stacking fault energetics, alters dislocation glide paths, and suppresses local phase transformations. Discrete dislocation dynamics simulations capture the strain-rate–dependent evolution of collective dislocation behavior. These results highlight the coupled roles of strain rate and SRO in governing plasticity in concentrated solid-solution alloys and provide mechanistic insight into rate-sensitive deformation in CrCoNi. |
| Proceedings Inclusion? |
Undecided |