Enhanced mechanical properties of a novel spinodal metallic network nanomaterial with preferentially aligned pore channels

Abstract

Nanoporous gold (NPG) possesses excellent physical and chemical properties, exhibiting widespread application potential. To enhance its mechanical performance, this study proposes a novel NPG architecture featuring preferentially aligned pore channels (pa-NPG) and systematically compares its mechanical behavior with that of conventional homogeneous NPG (h-NPG). Using phase-field modeling and molecular dynamics simulations, we generate both structures with various solid volume fractions. Uniaxial compression tests reveal that pa-NPG achieves a comprehensive enhancement in mechanical properties. Its elastic modulus is 30%–55% higher, and its energy absorption per unit volume exceeds that of h-NPG by 6.9%–16.5%. Scaling-law analysis of elastic modulus indicates that while h-NPG follows a classical bending-dominated behavior (exponent ∼2), pa-NPG manifests a hybrid mechanism dominated by combined ligament axial compression and bending. A modified Gibson–Ashby scaling law is proposed to describe the elastic behavior of pa-NPG. During the plateau regime, pa-NPG exhibits a higher density of HCP atoms, indicating stronger stacking fault/dislocation activity, which contributes to its sustained hardening and higher plateau stress. Furthermore, the deformation of individual ligaments confirms the significantly greater contribution of ligament axial compression in pa-NPG compared to the predominantly bending-dominated response in h-NPG, providing direct microstructural evidence for its enhanced load-bearing efficiency. These microstructural responses lead to a higher plateau stress and superior specific energy absorption in pa-NPG. This work provides a promising design strategy for lightweight structural materials with tailored mechanical performance.