Ligament-Size Effects on the Mechanical Behavior of Au/Cu Dual-Phase Spinodoid Nanocubes

Spinodoid nanocubes, inspired by spinodal decomposition, feature bicontinuous dual-phase architectures with high interfacial area, offering a promising platform for tuning nanoscale mechanics. In the present study, classical molecular dynamics simulations are carried out to investigate the mechanical properties and deformation behaviors of Au/Cu dual-phase spinodoid nanocubes. It is revealed that the ligament size of the spinodoid structure strongly influences material strength. As ligament size decreases, the strength of nanocubes increases until reaching a critical threshold, beyond which further refinement induces softening. This transition is governed by the semi-coherent interfaces through two competing mechanisms: for ligament sizes above the critical threshold, interfaces primarily impede dislocation motion, thereby strengthening the material; for smaller ligaments, interfacial plasticity, such as atomic rearrangements within the interface, provides a dominant softening mechanism. These findings highlight the critical role of characteristic length scale in determining the strength of nanocubes, and offer guidance for tailoring the mechanical performance of nanoscale dual-phase materials through structural design.