Mechanism transition and strong temperature dependence of dislocation nucleation from grain boundaries: An accelerated molecular dynamics study

Jun-Ping Du, Yun-Jiang Wang, Yu-Chieh Lo, Liang Wan, and Shigenobu Ogata
Phys. Rev. B 94, 104110 – Published 14 September 2016
PDFHTMLExport Citation

Abstract

Accelerated molecular dynamics reveals a mechanism transition and strong temperature dependence of dislocation nucleation from grain boundaries (GBs) in Cu. At stress levels up to 90% of the ideal dislocation-nucleation stress, atomic shuffling at the E structural unit in a GB acts as a precursor to dislocation nucleation, and eventually a single dislocation is nucleated. At very high stress levels near the ideal dislocation-nucleation stress, a multiple dislocation is collectively nucleated. In these processes, the activation free energy and activation volume depend strongly on temperature. The strain-rate dependence of the critical nucleation stress is studied and the result shows that the mechanism transition from the shuffling-assisted dislocation-nucleation mechanism to the collective dislocation-nucleation mechanism occurs during the strain rate increasing from 104s1to1010s1.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
1 More
  • Received 24 May 2016
  • Revised 6 August 2016

DOI:https://doi.org/10.1103/PhysRevB.94.104110

©2016 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Jun-Ping Du1,2, Yun-Jiang Wang3,4,*, Yu-Chieh Lo5, Liang Wan2,6, and Shigenobu Ogata2,1,†

  • 1Center for Elements Strategy Initiative for Structural Materials (ESISM), Kyoto University, Sakyo, Kyoto 606-8501, Japan
  • 2Department of Mechanical Science and Bioengineering, Osaka University, Osaka 560-8531, Japan
  • 3State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
  • 4School of Engineering Science, University of Chinese Academy of Sciences, Beijing 101408, China
  • 5Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu City 300, Taiwan
  • 6Center for Advancing Materials Performance from the Nanoscale, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China

  • *yjwang@imech.ac.cn
  • ogata@me.es.osaka-u.ac.jp

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 94, Iss. 10 — 1 September 2016

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×