Scaling behavior of stiffness and strength of hierarchical network nanomaterials

Abstract

Structural hierarchy can enhance the mechanical behavior of materials and systems. This is exemplified by the fracture toughness of nacre or enamel in nature and by human-made architected microscale network structures. Nanoscale structuring promises further strengthening, yet macroscopic bodies built this way contain an immense number of struts, calling for scalable preparation schemes. In this work, we demonstrated macroscopic hierarchical network nanomaterials made by the self-organization processes of dealloying. Their hierarchical architecture affords enhanced strength and stiffness at a given solid fraction, and it enables reduced solid fractions by dealloying. Scaling laws for the mechanics and atomistic simulation support the observations. Because they expose the systematic benefits of hierarchical structuring in nanoscale network structures, our materials may serve as prototypes for future lightweight structural materials.

Exceptionally shear-stable and ultra-strong Ir-Ni-Ta high-temperature metallic glasses at micro/nano scales

“…A combination of high strength and extended deformability is desirable in engineering structural materials for enabling the next generation of light-weight structures and technologies [1][2][3][4]. However, the two features are nearly exclusive, i.e., increasing the strength is often accompanied by the sacrifice of the ductility.…”

Robust Metallic Actuators Based on Nanoporous Gold Rapidly Dealloyed from Gold–Nickel Precursors

“…During similar compressive tests, bulk np‐Au dealloyed from Au‐Ag precursors experienced early onset of plastic yielding; [ 14a ] yielding started at low stresses below a few MPa (e.g., Figure 2b in ref. [ 14a ] ), or immediate plastic yielding happened even at the lowest strain with no distinguishable yield point (e.g., Figure 2a in ref. [ 14b ] , Figure 4 in ref.…”

“…[ 14a ] ), or immediate plastic yielding happened even at the lowest strain with no distinguishable yield point (e.g., Figure 2a in ref. [ 14b ] , Figure 4 in ref. [ 52 ] ).…”

“…Furthermore, due to the low relative density (solid fraction) and poor network connectivity, [ 13 ] np‐Au is vulnerable to early onset of plastic yielding, or even continuous plastic deformation upon compressive loading of a few MPa on macroscopic samples, [ 14 ] which can be worse than the predication from Gibson‐Ashby's open‐foam theory. [ 15 ] This limits applications that require certain structure stiffness to bear and output load such as actuators.…”

Hierarchically Interconnected Piezoceramic Textile with a Balanced Performance in Piezoelectricity, Flexibility, Toughness, and Air Permeability

“…In the past few years, hierarchical architecture has been introduced into structural and functional materials for multifarious applications such as adsorption, separation, catalysis, energy storage, and bioengineering. [25][26][27][28][29][30][31] Hierarchical structures possess a number of beneficial properties (e.g., large surface areas, tunable pore structure, good air permeability, high flexibility, and intensive compressive strength), [32][33][34][35][36] which makes them attractive candidates for biomechanical energy harvesting where both the flexibility and the high output are urgently required. Recently, there have been some reports on the hierarchical structures applied to energy harvesters (i.e., piezoelectric nanogenerators [37][38][39][40][41][42] and triboelectric nanogenerators [43][44][45] ).…”