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Title: Deformation mechanisms of Cu nanowires with planar defects

Molecular dynamics simulations are used to investigate the mechanical behavior of Cu nanowires (NWs) with planar defects such as grain boundaries (GBs), twin boundaries (TBs), stacking faults (SFs), etc. To investigate how the planar defects affect the deformation and fracture mechanisms of naowires, three types of nanowires are considered in this paper: (1) polycrystalline Cu nanowire; (2) single-crystalline Cu nanowire with twin boundaries; and (3) single-crystalline Cu nanowire with stacking faults. Because of the large fraction of atoms at grain boundaries, the energy of grain boundaries is higher than that of the grains. Thus, grain boundaries are proved to be the preferred sites for dislocations to nucleate. Moreover, necking and fracture prefer to occur at the grain boundary interface owing to the weakness of grain boundaries. For Cu nanowires in the presence of twin boundaries, it is found that twin boundaries can strength nanowires due to the restriction of the movement of dislocations. The pile up of dislocations on twin boundaries makes them rough, inducing high energy in twin boundaries. Hence, twin boundaries can emit dislocations, and necking initiates at twin boundaries. In the case of Cu nanowires with stacking faults, all pre-existing stacking faults in the nanowires are observedmore » to disappear during deformation, giving rise to a fracture process resembling the samples without stacking fault.« less
Authors:
; ;  [1] ;  [2] ;  [3]
  1. College of Mechanics and Materials, HoHai University, Nanjing 210098 (China)
  2. LSEC, ICMSEC, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100190 (China)
  3. School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China)
Publication Date:
OSTI Identifier:
22412962
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPUTERIZED SIMULATION; COPPER; DEFORMATION; DISLOCATIONS; FRACTURES; GRAIN BOUNDARIES; INTERFACES; MOLECULAR DYNAMICS METHOD; MONOCRYSTALS; NANOWIRES; POLYCRYSTALS; STACKING FAULTS