Classical molecular dynamics simulation of atomic structure transitions in FeSiCuMgAl high-entropy alloys under biaxial stretching

Abstract

Classical molecular dynamics (MD) simulations were utilized in this study to investigate the mechanical properties of the crystal structure of high-entropy alloys under various mechanical stress conditions. The stress-strain behaviors and the merging of the crystal structure growth of FeSiCuMgAl high-entropy alloys during biaxial tensile deformation were simulated. Three stages of atomic structure transformation were observed during biaxial stretching of FeSiCuMgAl high-entropy alloys at a strain rate of 1010 s−1. In the first stage, the structure transitioned from face-centered cubic (fcc) to body-centered cubic (bcc), hexagonal close-packed (hcp), and disordered structures. The second stage involved a transition from bcc, hcp, and disordered structures to fcc. The third and final stage involved a transition from fcc, bcc, and hcp to disordered structure. To gather more information about the simulation process, this research simulated MD by varying the strain rate of tensile deformation. At a strain rate as low as 0.5×109 s−1 and below, there was minimal involvement of the bcc phase in the tensile process. During the simulation work, co-neighborhood analysis, stress-strain analysis, and dislocation analysis were utilized to accurately describe the simulated tensile behavior. The simulation results will provide more insights into the design and preparation of high-entropy alloys as foundational materials.