Self-Healing of Nanoporous Gold Under Ambient Conditions.
Failure of a material is an irreversible process since the material loses its original characteristics and properties. The catastrophic brittle failure under tensile stress of nanoporous gold (np-Au) with a bicontinuous open-cell structure makes impossible otherwise attractive applications. Here, we first demonstrate a self-healing process in tensile-fractured np-Au to overcome the limit of fragility via mechanically assisted cold-welding under ambient conditions. The self-healing ability of np-Au in terms of mechanical properties shows strength recovery up to 64.4% and fully recovered elastic modulus compared with initial tensile properties. Topological parameters obtained by three-dimensional reconstruction of self-healed np-Au clarify the strength, elastic modulus, and strain distribution. The self-healing process in np-Au is attributed to surface diffusion expedited by local compressive stress in the ultrasmall dimension of ligaments formed by ductile failures of individual ligaments.
['Gwak|Eun-Ji|EJ|', 'Jeon|Hansol|H|', 'Song|Eunji|E|', 'Kim|Ju-Young|JY|http://orcid.org/0000-0002-3096-1350']
self-healing nanoporous gold strength recovery surface diffusion compressive stress