Influence of twinning thickness on the mechanical properties of crystalline-amorphous dual-phase CoCrFeNiMn high entropy alloy

This study employs molecular dynamics simulation to investigate the influence of twin thickness on the mechanical properties and plastic deformation mechanisms for crystalline/amorphous dual-phase CoCrFeNiMn high-entropy alloy with varying amorphous layer thicknesses. The results revealed that for a minor amorphous layer thickness ( d ) of 1 nm, increasing the twin thickness ( h ) decreased average flow stress and peak stress within the models. It can be attributed to the fact that at smaller h , twin boundaries effectively hinder dislocation motion. However, as h increases, dislocation storage near twin boundaries and subsequent large-scale FCC→HCP phase transformation become more robust, reducing stress. On the other hand, when d thickness increases to 7 nm, stable average flow stress is observed due to thicker shear band formation during plastic deformation. Regardless of whether d was 1 nm or 7 nm, an increase in twin thickness augmented the likelihood of FCC→HCP phase transformation.