Mechanical behavior of high entropy alloys with gyroid nanostructures

VL Nguyen and MQ Doan and DTH Hue and VH Dinh and LV Lich, INTERMETALLICS, 171, 108348 (2024).

DOI: 10.1016/j.intermet.2024.108348

High-entropy alloys have attracted growing attention due to their outstanding mechanical properties. Recent advances in nanofabrication offer novel avenues for customizing material properties via precise control over cellular nanostructures. However, comprehending the relationship between high-entropy alloy structures and mechanical properties when coupled with artificial nanostructures poses a persistent challenge. This study investigates the mechanical characteristics of high-entropy alloys with gyroid nanostructures using molecular dynamics simulations. The findings illustrate the ability to mitigate strain softening by manipulating the relative densities. The change of densities in gyroid nanostructures directly influences mechanical responses, evident in the decrease of Young's modulus and tensile strength with diminishing density. The study observes different plastic deformation behaviors, with high-density gyroid nanostructures exhibiting prevalent strain softening, contrasting with low-density counterparts that exhibit different dislocation evolution patterns, thereby lacking this softening behavior. The present study emphasizes the pivotal role of the gyroid struts and nodes in determining mechanical properties, highlighting the presence of strain softening in node-dominant nanostructures and its absence in the strut-dominant ones. Furthermore, both the yielding stress and ultimate tensile strength of gyroid nanostructures surpass those of stochastic bicontinuous nanostructures at equivalent relative densities.

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