Tailoring strength and ductility in dual-phase high-entropy alloys: Insights from deep learning molecular dynamics simulation on FCC/BCC thickness ratios

This study investigates the influence of FCC/BCC thickness ratios on the mechanical properties of AlCoCrFeNi dual-phase high-entropy alloys (DP-HEAs) using deep learning-enhanced molecular dynamics simulations. The results demonstrate that varying the thickness ratio significantly affects the stress-strain behavior, dislocation density evolution, and local structural transformations during tensile deformation. DP_0.5, with a thinner BCC phase, exhibits higher dislocation densities and enhanced strain hardening, resulting in increased strength but reduced ductility. In contrast, DP_3.0, with a thicker BCC phase, shows lower dislocation densities, leading to improved ductility but lower strength. The phase transformation from BCC to HCP structures is a key mechanism contributing to plastic deformation, with the BCC/FCC interface playing a critical role in dislocation nucleation and propagation. These findings provide valuable insights into optimizing the microstructural design of DP-HEAs to achieve a tailored balance of strength and ductility, offering the potential for advanced structural applications.