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

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2017-07, Vol.13 (25), p.n/a
• Main Authors: Yue, Yonghai, Zhang, Qi, Zhang, Xuejiao, Yang, Zhenyu, Yin, Penggang, Guo, Lin
• Format: Article
• Language: English
• Subjects: Crystal structure; Deformation; Deformation mechanisms; Dislocations; Electrons; in situ; Microstructure; Migration; Molecular dynamics; Nanomaterials; Nanotechnology; Nanowires; Necking; single crystalline Cu nanowires; Sliding; Strain; Transmission electron microscopy; twin boundary sliding
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201604296

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. In situ observation of twin boundary sliding (TBS) caused by full dislocation (extended dislocation) is first revealed at the atomic scale. Combined with twin boundary migration and multiple dislocations nucleated from the surface, TBS causes a fracture strain of ≈166% and a severe necking of ≈93%, far beyond the typical values for most nanomaterials without twins.