点击次数：

影响因子：18.9

DOI码：10.1038/s41467-021-25542-2

发表刊物：Nature Communications

摘要：Ultrahigh surface-to-volume ratio in nanoscale materials, could dramatically facilitate mass transport, leading to surface-mediated diffusion similar to Coble-type creep in polycrystalline materials. Unfortunately, the Coble creep is just a conceptual model, and the associated physical mechanisms of mass transport have never been revealed at atomic scale. Akin to the ambiguities in Coble creep, atomic surface diffusion in nanoscale crystals remains largely unclear, especially when mediating yielding and plastic flow. Here, by using in situ nanomechanical testing under high-resolution transmission electron microscope, we find that the diffusion-assisted dislocation nucleation induces the transition from a normal to an inverse Hall-Petch-like relation of the strength-size dependence and the surface-creep leads to the abnormal softening in flow stress with the reduction in size of nanoscale silver, contrary to the classical “alternating dislocation starvation” behavior in nanoscale platinum. This work provides insights into the atomic-scale mechanisms of diffusion-mediated deformation in nanoscale materials, and impact on the design for ultrasmall-sized nanomechanical devices.

合写作者：Shuhei Shinzato, Zhengwu Fang, Yang He, Li Zhong, Chongmin Wang, Shigenobu Ogata

第一作者：Xiang Wang, Sixue Zheng

论文类型：期刊论文

通讯作者：Scott X Mao

学科门类：工学

文献类型：J

卷号：12

期号：1

页面范围：5237

是否译文：否

发表时间：2021-09-02

收录刊物：SCI

发布期刊链接：https://doi.org/10.1038/s41467-021-25542-2