Nanoporous gold (NPG) provides a model material for studying small-scale deformation and the mechanical behavior of network solids. We report a transmission electron microscopy study of the defect structure in electron-transparent NPG leaf deformed by rolling. The results confirm that plastic deformation significantly enhances the defect density. Specifically, twins are formed on several sets of crystallographic planes, and their interaction forms Lomer-Cottrell locks. This inhibits dislocation escaping from NPG, thus avoiding the dislocation starvation scenario that is often considered in the ‘smaller is stronger' context of small-scale plasticity. Instead, strain hardening is apparently linked to accumulation and interaction of twins.

纳米多孔金（NPG）为研究小规模变形和网络固体的机械行为提供了模型材料。我们报告了透射电子显微镜研究的轧制变形的电子透明NPG叶片中的缺陷结构。结果证实塑性变形显着提高了缺陷密度。具体来说，孪晶在几组晶体学平面上形成，它们的相互作用形成了Lomer-Cottrell锁。这抑制了位错从NPG逸出，从而避免了在小规模可塑性的“小而强”背景下经常考虑的位错饥饿的情况。相反，应变硬化显然与孪晶的积累和相互作用有关。