Impact of Grain Boundaries on Structural and Mechanical Properties

  • H. Van Swygenhoven
  • P. M. Derlet
  • A. Hasnaoui
  • M. Samaras
Part of the NATO Science Series book series (NAII, volume 128)


For some polycrystalline metals with grain sizes in the nano regime, experiments have suggested a deviation away from the Hall-Petch relation relating yield stress to average grain size [1]. The debate continues whether or not such deviations are a result of intrinsically different material properties of nanocrystalline (nc) systems, or due simply to inherent difficulties in the preparation of fully dense nc-samples and in their microstructural characterization. Nevertheless, it suggests that the traditional work hardening mechanism of pile-up of dislocations originating from Frank-Read sources may no longer be valid at the nanometer scale. In-situ deformation testing in the transmission electron microscope (TEM), performed on Cu and Ni3Al nc samples, reveals a limited dislocation activity in grains below 50nm [2,3]. However, due to the presence of large internal stresses which make grain boundaries (GB) in TEM images difficult to observe, and also possible artifacts induced by thin-film geometry such as dislocations emitted from the surface [4], in-situ tensile tests did not until now, bring convincing evidence for abundant dislocation activity. Mechanical testing also revealed the issue of the “GB state” by means of a property dependence on thermal history and internal strains. It is shown that a substantial strengthening can be obtained by a short heat treatment. The cause of the strengthening is possibly associated with a reduction in internal strains and/or dislocation content produced by the annealing [5]. The effect of strengthening has been measured both on nc materials obtained by grain refinement techniques and those obtained by consolidation of clusters.


Grain Boundary Triple Junction Grain Boundary Slide Dislocation Activity Excess Free Volume 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Weertman, J.R. (2002) Mechanical behaviour of nanocrystalline metals, Nanostructured Materials: Processing, Properties, and Potential Applications, William Andrew Publishing, Norwich.Google Scholar
  2. 2.
    Youngdahl, C.J., Hugo, R.X., Kung, H. and Weertman, J.R. (2002), TEM observation of nanocrystalline copper during deformation, Structure and Mechanical Properties of Nanophase Materials-Theory and Computer Simulation vs. Experiment, MRS Symposium Series Vol. 634, B1.2.Google Scholar
  3. 3.
    McFadden, S.X., Sergueeva, A.V., Kruml, T., Martin, J-L. and Mukherjee, A.K. (2000), Superplasticity in nanocrystalline Ni3A1 and Ti Alloys, Structure and Mechanical Properties of Nanophase Materials-Theory and Computer Simulation vs. Experiment, MRS Symposium Series Vol. 634, B1.3.Google Scholar
  4. 4.
    Derlet, P.M. and Van Swygenhoven, H. (2001) The role played by two parallel free surfaces in the deformation mechanism of nanocrystalline metals: a molecular dynamics simulation, Phil. Mag. A. 82, 1–15.CrossRefGoogle Scholar
  5. 5.
    Volpp, T., Goring, E., Kuschke, W.M. and Arzt, E. (1997) Grain size determination and limits to Hall-Petch behaviour in nanocrystalline NiAl powders, Nanostruct. Mater. 8, 855–865.CrossRefGoogle Scholar
  6. 6.
    Van Swygenhoven, H. (2002) Polycrystalline materials: grain boundaries and dislocations, Science 296, April 4, 66–67.CrossRefGoogle Scholar
  7. 7.
    Van Swygenhoven, H., Farkas, D. and Caro, A. (2000) Grain-boundary structures in polycrystalline metals at the nanoscale, Phys. Rev. B 62, 831–838.CrossRefGoogle Scholar
  8. 8.
    Cleri F. and Rosato, V. (1993) Tight binding potentials for transition metals and alloys, Phys. Rev. B 48, 22–33CrossRefGoogle Scholar
  9. 9.
    Honeycutt D. J. and Andersen H. C. (1987) Molecular dynamics study of melting and freezing of small Lennard-Jones Clusters, J. Phys. Chem. 91, 4950–4963CrossRefGoogle Scholar
  10. 10.
    Derlet, P. M. and Van Swygenhoven, H. (2002) Atomic Positional Disorder in Fee Metal Nanocrystalline Grain Boundaries, Phys. Rev. B., 67, 014202–8.CrossRefGoogle Scholar
  11. 11.
    Van Swygenhoven, H. and Derlet, P.M. (2001) Grain-boundary sliding in nanocrystalline fcc metals, Phys. Rev. B 64, 224105–9.CrossRefGoogle Scholar
  12. 12.
    Yamakov. V., Wolf, D., Salazar, M., Phillpot, S.R. and Gleiter, H. (2001) Length-scale effects in the nucleation of extended dislocations in nanocrystalline al by MD simulations, Acta Mater. 49, 2713–2722.CrossRefGoogle Scholar
  13. 13.
    Derlet, P.M. and Van Swygenhoven, H. (2002) Length scale effects in the simulation of deformation properties of nanocrystalline metals, Scripta Mater. 47, 719–724.CrossRefGoogle Scholar
  14. 14.
    Van Swygenhoven, H,. Derlet, P.M. and Hasnaoui, A. (2002) Atomic mechanism for dislocation emission from nanosized grain boundaries, Phys. Rev. B 66, 024101–8.CrossRefGoogle Scholar
  15. 15.
    Hasnaoui, A., Van Swygenhoven, H. and Derlet, P.M. (2002) Cooperative processes during plastic deformation in nanocrystalline fcc metals — a molecular dynamics simulation, Phys. Rev. B 66 184112–8.CrossRefGoogle Scholar
  16. 16.
    Hasnaoui, A., Van Swygenhoven, H. and Derlet, P.M. (2002) On non-equilibrium grain boundaries and their effect on thermal and mechanical behaviour: a molecular dynamics computer simulation, Acta Mater. 50, 3927–3939.CrossRefGoogle Scholar
  17. 17.
    Gerberich, W. W., Nelson, J. C., Lilleoddem, E. T., Anderson, P., and Wryobek, J. T. (1996) Indentation induced dislocation nucleation: the initial yield point, Acta. Mater. 44 3585–3598.CrossRefGoogle Scholar
  18. 18.
    Gouldstone, A., Koh, H.-J., Zeng, K.-Y., Giannakopoulos, and Suresh, S. (2000) Discrete and continuous deformation during nanoindentation of thin films, Acta. Mater. 48 2277–2295.CrossRefGoogle Scholar
  19. 19.
    Zimmermann, J. A., Kelchner, C. L., Klein, P. A., Hamilton, J. C, and Foiles, S. (2001) Surface step effects on nonoindentation, Phys. Rev. Lett. 87, 165507–4.CrossRefGoogle Scholar
  20. 20.
    Feichtinger, D., Derlet, P. M., and Van Swygenhoven, H. (2003) Atomistic simulations of spherical indentations in nanocrystalline Gold, Phys. Rev. B., 67, 024113–4.CrossRefGoogle Scholar
  21. 21.
    Rose, M., Balogh, A. G., and Hahn, H. (1997) Instability of irradiation induced defects in nanostructured materials, Nuc. Inst. Meth. Phys. Res. B 127/128 119–122.CrossRefGoogle Scholar
  22. 22.
    Samaras, M., Derlet, P. M., Van Swygenhoven, H., and Victoria, M. (2002) On non-equilibrium grain boundaries and their effect on thermal and mechanical behaviour: a molecular dynamics computer simulation, Phys. Rev. Lett. 88, 125505–4.CrossRefGoogle Scholar
  23. 23.
    Samaras, M., Derlet, P. M., Van Swygenhoven, H., and Victoria, M. (2003) SIA Activity during irradiation of nanocrystalline Ni, J. of Nucl. Mater., Submitted.Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2003

Authors and Affiliations

  • H. Van Swygenhoven
    • 1
  • P. M. Derlet
    • 1
  • A. Hasnaoui
    • 1
  • M. Samaras
    • 1
  1. 1.Paul Scherrer InstituteVilligen-PSISwitzerland

Personalised recommendations