Cyclic Plasticity of CoCrFeMnNi High-Entropy Alloy (HEA): A Molecular Dynamics Simulation

Abstract

The CoCrFeMnNi high-entropy alloy (HEA) is a potential structural material, whose cyclic plasticity is essential for its safety assessment in service. Here, the effects of twin boundaries (TBs) and temperature on the cyclic plasticity of CoCrFeMnNi HEA were studied by the molecular dynamics (MD) simulation. The simulation results showed that a significant amount of lattice disorders were generated due to the interactions between partial dislocations in CoCrFeMnNi HEA during the cyclic deformation. Lattice disorder impeded the reverse movement of dislocations and then weakened Bauschinger’s effect in the HEA. The cyclic plasticity of CoCrFeMnNi HEA, especially Bauschinger’s effect, depends highly on the temperature and pre-existing TBs. Such dependence lies in the effects of temperature and pre-existing TBs on the extent of lattice disorder. This study helps further understand the cyclic plasticity of CoCrFeMnNi HEA from the atomic scale.