Bauschinger effect on high entropy alloy under cyclic deformation

This study employs molecular dynamics (MD) simulations to examine materials with comparable tension-compression behavior but markedly different cyclic fatigue performances. The findings reveal that the cyclic fatigue properties of AlCoCrCuFeNi high-entropy alloys (HEAs) are primarily governed by microscopic deformation mechanisms, particularly dislocation slip modes, which subtly affect initial work hardening. However, the slight initial differences in work hardening affected by the butterfly and Bauschinger effects gradually accumulate and intensify with repeated fatigue cycling. As the number of loading cycles increases, β-asymmetry steadily declines. Interactions between partial dislocations and stacking faults (SFs) at lower temperatures disrupt the lattice structure and impede dislocation reversal, thereby diminishing the Bauschinger effect. This mechanism contributes to marked variations in fatigue life and cyclic stress response.