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Deforming Nanocrystalline Metals: New Insights, New Puzzles

  1. Dr. Jörg Weissmüller1,2,
  2. Jürgen Markmann1,2

Published Online: 15 NOV 2007

DOI: 10.1002/3527600434.eap651

Encyclopedia of Applied Physics

Encyclopedia of Applied Physics

How to Cite

Weissmüller, J. and Markmann, J. 2007. Deforming Nanocrystalline Metals: New Insights, New Puzzles. Encyclopedia of Applied Physics. .

Author Information

  1. 1

    Forschungszentrum Karlsruhe, Institut für Nanotechnologie, Karlsruhe, Germany

  2. 2

    Universität des Saarlandes, Technische Physik, Saarbrücken, Germany

Publication History

  1. Published Online: 15 NOV 2007

Abstract

Recent experiments have brought new insights into the mechanisms which govern the plasticity of nanocrystalline metals. In particular, new opportunities have arisen from the finding that bulk nanocrystalline samples with extremely small grain size, prepared by the inert gas condensation technique, can be deformed to large true strain. The findings elucidate the roles of creep, partial dislocation activity along with its consequences, faulting and twinning, as well as grain boundary sliding and grain rotation. However, they also rise intriguing new questions, specifically with respect to the mechanisms of dislocation nucleation at grain boundaries, and with respect to slip system selection and alignment in twinned grains. An emerging insight is that there is not ‘the’ deformation mechanism at small grain size; instead, deformation mechanism maps in, for instance, the parameter space spanned by the strain rate and the grain size, are more appropriate representations of the various processes that control the materials behavior.