单晶铜纳米线中孪晶界滑动的原位观察

In Situ Observation of Twin Boundary Sliding in Single Crystalline Cu Nanowires.

作者信息

Yue Yonghai, Zhang Qi, Zhang Xuejiao, Yang Zhenyu, Yin Penggang, Guo Lin

机构信息

Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, Beijing Key Laboratory of Bio-inspired Energy Materials and Devices, School of Chemistry, Beihang University, Beijing, 100191, P. R. China.

Institute of Solid Mechanics, Beihang University, Beijing, 100191, P. R. China.

出版信息

Small. 2017 Jul;13(25). doi: 10.1002/smll.201604296. Epub 2017 May 16.

DOI:10.1002/smll.201604296

PMID:28508522

Abstract

Using a homemade, novel, in situ transmission electron microscopy (TEM) double tilt tensile device, plastic behavior of single crystalline Cu nanowires of around 150 nm are studied. Deformation twins occur during the tests as predesigned before the experiments. In situ observation of twin boundary sliding (TBS) caused by full dislocation (extended dislocation) is first revealed at the atomic scale which is confirmed by molecular dynamics (MD) simulation results. Combined with twin boundary migration and multiple dislocations nucleated from surface, TBS causes a superlarge fracture strain which is over 166% and a severe necking which is over 93%, far beyond the typical values for most nanomaterials without twins.

摘要

使用自制的、新颖的原位透射电子显微镜（TEM）双倾斜拉伸装置，研究了直径约150 nm的单晶铜纳米线的塑性行为。测试过程中出现了如实验前预先设计的变形孪晶。首次在原子尺度上揭示了由全位错（扩展位错）引起的孪晶界滑动（TBS）的原位观察结果，这一结果得到了分子动力学（MD）模拟结果的证实。结合孪晶界迁移和从表面形核的多个位错，TBS导致了超过166%的超大断裂应变和超过93%的严重颈缩，远远超出了大多数无孪晶纳米材料的典型值。