Unveiling the compressive behavior of Fe2Ni2CrAl high entropy alloy: A combined molecular dynamics and finite element study

L Qiao and JC Zhu, MATERIALS TODAY COMMUNICATIONS, 34, 105296 (2023).

DOI: 10.1016/j.mtcomm.2022.105296

As promising materials in structural application field, currently developed Fe2Ni2CrAl high entropy alloys (HEAs) exhibited high strengths and good plasticity. In this work, multi-scale computational method was utilized to reveal its mechanical behavior at room and elevated temperatures. Mechanical properties of Fe2Ni2CrAl HEAs at different temperatures were implemented into FEM model to analyze the deformation behavior at the relevant length scales. Simulated stress-strain curves were highly consistent with the experimental value. The distribution of stress, strain and displacement obtained from FEM simulation were captured in the deformed samples. At the atomic scale, deformation behavior at temperature of (300 K, 673 K, 873 K and 1073 K) was simulated by molecular dynamics (MD). The physical mechanisms including phase transformation, dislocation mobility and twinning were uncovered during deformation. A series of shear bands (SBs) formed and propagated as the strain increased and induced the phase transformation. Strengthening in mechanical behavior was achieved by dislocation interactions and twinning, associated with random local concentration fluctuations. At all temperatures, the movements of stacking fault (SFs) released and led by Shockley partial dislocation under compression. This work accelerated the theoretical understanding in the strengthening and deformation mechanisms at multiscale levels.

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