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Shear response of grain boundaries with metastable structures by molecular dynamics simulations

Journal Article


Abstract


  • Grain boundaries (GBs) can play a role as the favored locations to annihilate point

    defects, such as interstitial atoms and vacancies. It is thus highly probable that

    different boundary structures can be simultaneously present in equilibrium with each

    other in the same GB, and thus the GB achieves a metastable state. However, the

    structural transition and deformation mechanism of such GBs are currently not well

    understood. In this work, molecular dynamics simulations were carried out to study

    the multiple structures of a Σ5(310)/[001] GB in bicrystal Al and to investigate the

    effect of structural multiplicity on the mechanical and kinetic properties of such a

    GB. Different GB structures were obtained by changing the starting atomic configuration

    of the bicrystal model, and the GB structures had significantly different

    atomic density. For the Σ5(310) GB with metastable structures, GB sliding was the

    dominant mechanism at a low temperature (T=10K) under shear stress. The

    sliding mechanism resulted from the uncoordinated transformation of the inhomogeneous

    structural units. The nucleation of voids was observed during GB

    sliding at the low temperature, and the voids subsequently evolved to a nanocrack at

    the boundary plane. Increasing the temperature can induce the structural transition of

    local GB structures and can change their overall kinetic properties. GB migration

    with occasional GB sliding dominated the deformation mechanism at elevated

    temperatures (T=300 and 600 K), and the migration process of the metastable GB

    structures is closely related to the thermally assisted diffusion mechanism.

Authors


  •   Zhang, Liang (external author)
  •   Lu, Cheng
  •   Shibuta, Yasushi (external author)

Publication Date


  • 2018

Citation


  • Zhang, L., Lu, C. & Shibuta, Y. (2018). Shear response of grain boundaries with metastable structures by molecular dynamics simulations. Modelling And Simulation In Materials Science And Engineering, 26 (3), 035008-1-035008-20.

Scopus Eid


  • 2-s2.0-85044407309

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers1/1915

Start Page


  • 035008-1

End Page


  • 035008-20

Volume


  • 26

Issue


  • 3

Place Of Publication


  • United Kingdom

Abstract


  • Grain boundaries (GBs) can play a role as the favored locations to annihilate point

    defects, such as interstitial atoms and vacancies. It is thus highly probable that

    different boundary structures can be simultaneously present in equilibrium with each

    other in the same GB, and thus the GB achieves a metastable state. However, the

    structural transition and deformation mechanism of such GBs are currently not well

    understood. In this work, molecular dynamics simulations were carried out to study

    the multiple structures of a Σ5(310)/[001] GB in bicrystal Al and to investigate the

    effect of structural multiplicity on the mechanical and kinetic properties of such a

    GB. Different GB structures were obtained by changing the starting atomic configuration

    of the bicrystal model, and the GB structures had significantly different

    atomic density. For the Σ5(310) GB with metastable structures, GB sliding was the

    dominant mechanism at a low temperature (T=10K) under shear stress. The

    sliding mechanism resulted from the uncoordinated transformation of the inhomogeneous

    structural units. The nucleation of voids was observed during GB

    sliding at the low temperature, and the voids subsequently evolved to a nanocrack at

    the boundary plane. Increasing the temperature can induce the structural transition of

    local GB structures and can change their overall kinetic properties. GB migration

    with occasional GB sliding dominated the deformation mechanism at elevated

    temperatures (T=300 and 600 K), and the migration process of the metastable GB

    structures is closely related to the thermally assisted diffusion mechanism.

Authors


  •   Zhang, Liang (external author)
  •   Lu, Cheng
  •   Shibuta, Yasushi (external author)

Publication Date


  • 2018

Citation


  • Zhang, L., Lu, C. & Shibuta, Y. (2018). Shear response of grain boundaries with metastable structures by molecular dynamics simulations. Modelling And Simulation In Materials Science And Engineering, 26 (3), 035008-1-035008-20.

Scopus Eid


  • 2-s2.0-85044407309

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers1/1915

Start Page


  • 035008-1

End Page


  • 035008-20

Volume


  • 26

Issue


  • 3

Place Of Publication


  • United Kingdom