CIRP Encyclopedia of Production Engineering

2014 Edition
| Editors: The International Academy for Production Engineering, Luc Laperrière, Gunther Reinhart

Deformation (Dislocations)

Reference work entry


Deviations from the strictly geometrical lattice structure (Schmid and Boas 1950). Alternatively, an interfacial region whose advance causes a fully slipped region to grow at the expense of an unslipped region (Cottrell 1967).

Theory and Application


Large plastic deformation can be identified by the accumulation of slips at the macroscopic scale as well as at the atomic scale. During tensile deformation, metal blocks slip on slip planes and rotate, as schematically illustrated in Fig. 1. Increasing plastic deformation results in numerous cross slips. Such slips can be observed as Lüders bands in annealed low-carbon steel subjected to tensile deformation. From the macroscopic viewpoint, this is a visible example that proves that plastic deformation involves the accumulation of slips on slip planes. Such slips at the atomic scale are called dislocations, which are deviations from the strictly geometrical lattice structure (Schmid and Boas 1950). Dislocations are...
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The author would like to express sincere thanks to Dr. Kosaku Ushioda of Nippon Steel for permission to reproduce the TEM images of steels in this entry.


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Copyright information

© CIRP 2014

Authors and Affiliations

  1. 1.Institute of Industrial ScienceThe University of TokyoTokyoJapan