Investigating Dislocation Behavior in High Entropy Alloys Using Atomistic Simulations

Abstract

High-entropy alloy (HEA) is a new alloying strategies involving multi-principal elements in near equiatomic proportions.[39, 11, 37, 19, 41, 13] To fully understand and tune the mechanical properties and crystal plasticity of the alloys, it is necessary to investigate the dislocation behavior[15]. The NiCoCr system is reported to have a single-phase face-centered cubic (FCC) crystal structure with enhanced mechanical properties compared to conventional alloys. Its negative stacking fault energy and high yield strength allows unique dislocation behavior. Also, the annealing temperature of NiCoCr system leads to a wide range of short range orders which directly affect the energy barrier of dislocation movement.[22] This work investigates the flow stresses in various systems under constant strain rate and the relationship between partial dislocation behavior and stacking fault energy of NiCoCr system.