Deformation behavior of nanoporous gold based composite in compression: A finite element analysis

摘要

Integrating a polymer into the nanoporous metals (NPMs) could efficiently reduce the density change during plastic flow with better ductilization, which widens great potential applications of nanocomposites. In this work, a finite element model of stochastic bicontinuous nanoporous structure is generated for the first time. A nanocomposite material is generated by fitting a polymer into the pore space of NPMs, and the mechanical behaviors of the composite of nanoporous gold (npg) and epoxy under uniaxial compression are investigated via finite element analysis. Results show that the stress is mainly concentrated at the ligament necks rather than junctions of the npg constitute phase and the epoxy constitute phase during deformation. In analogy to npg, the Young's modulus of npg-epoxy composite as a function of metal volume fraction displays a power-law relation and the yield stress has an approximately linear relation. It is worth noticing that the Young's modulus and the yield stress of nanocomposite exceeds that of each of its constituent phases and are higher than the sum of two pure phases. The present study provides new insights into the mechanical behaviors of npg-epoxy composite, as well as a practical guide for designing a new class of strong and ductile nanocomposites.