|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||High Entropy Alloys V
||New Deformation Twinning Mechanism in Equimolar Multi-component Alloys with Low Stacking Fault Energy
||Qingjie Li, Evan Ma
|On-Site Speaker (Planned)
Single-phase FCC equimolar multi-component alloys (EMAs) such as CrMnFeCoNi and NiCrCo often exhibit an unusual combination of high tensile strength and ductility. Such an extraordinary strength-ductility synergy is believed to be closely related to the hierarchical deformation twinning (DT) microstructures developed in these alloys, however it is unclear how the profuse deformation twins form. Using molecular dynamics simulations with realistic EAM potentials, we demonstrate a new DT mechanism that takes advantage of the intersection between faults. These intersections are of glide-like symmetry in lieu of the screw symmetry in the conventional pole mechanism. The translational component of this glide-like symmetry plays the role of promoter to mediate DT, constituting the source of twinning dislocations. This new mechanism is especially prolific at high driving stresses, explaining the enhanced occurrence of hierarchical twin structures in EMAs at cryogenic deformation temperatures.
||Planned: Supplemental Proceedings volume