Dislocation Motion in Single-Phase High Entropy Alloys – Theory and Simulation

High entropy alloys (HEAs) are chemically complex single-phase alloys with simple crystal structure. They are a novel class of alloy systems with five or more elements at near equiatomic composition with the potential of achieving non-incremental advances in mechanical properties. It is assumed that the high configurational entropy in these alloys stabilizes the single phase despite a significant energetic cost, as the disordered arrangement of atoms implies large atomic-scale lattice distortions. The simultaneous presence of crystalline order and compositional disorder endows single phase HEAs with unusual thermodynamic and kinetic properties. HEAs have been shown to possess interesting mechanical properties, such as low weight to strength ratio, combination of high strength and toughness, etc. The primary aim of this project is to understand the strengthening mechanism in HEAs by studying dislocation motion in such structure and provide information for mesoscale models ( Prof. Zaiser, WW8). An example for a model fcc-HEA is AlCoCuNiFe that is shown in the figure here.