3D printed self-similar AlSi10Mg alloy hierarchical honeycomb architectures under in-plane large deformation

Abstract

Self-similar hierarchical honeycombs with complicated cellular topologies are promising cores for lightweight sandwich structures ascribed to superior structural efficiency in terms of mitigating damage. In this paper, the in-plane compressive characteristics of AlSi10Mg alloy hierarchical honeycombs, fabricated using Selective Laser Melting (SLM) methodology, under large deformation are reported. The results suggest that higher hierarchies enhance the elastic modulus of honeycombs significantly, whereas the compressive strength is improved negligibly. There is a failure mechanism transition from cell wall bending dominated to cell wall fracture dominated with the increase of relative density and hierarchical order, and the failure mechanisms are related to the wall thickness with critical value of 0.345 mm. It is concluded that the in-plane failure of hierarchical honeycombs is dominated by the bending, axial compression and shear deformation of original unit cell walls. Besides, the parent material without heat treatment contributes to more excellent mechanical properties of hierarchical honeycombs owing to higher tensile strength and elastic modulus. This work enables to facilitate the structural design and optimization of high-performance hierarchical honeycomb metamaterials with desired properties and functions.