Microstructure Development of Copper Single Crystal Deformed by Equal Channel Angular Pressing

  1. Prof. Dr. Michael Zehetbauer3 and
  2. Prof. Ruslan Z. Valiev4
  1. Tetsuo Koyama1,
  2. Hiroyuki Miyamoto1,
  3. Takuro Mimaki1,
  4. Alexei Vinogradov2 and
  5. Satoshi Hashimoto2

Published Online: 28 JAN 2005

DOI: 10.1002/3527602461.ch6g

Nanomaterials by Severe Plastic Deformation

Nanomaterials by Severe Plastic Deformation

How to Cite

Koyama, T., Miyamoto, H., Mimaki, T., Vinogradov, A. and Hashimoto, S. (2004) Microstructure Development of Copper Single Crystal Deformed by Equal Channel Angular Pressing, in Nanomaterials by Severe Plastic Deformation (eds M. Zehetbauer and R. Z. Valiev), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, FRG. doi: 10.1002/3527602461.ch6g

Editor Information

  1. 3

    Institut für Materialphysik, Universität Wien, Boltzmanngasse 5, 1090 Wien, Austria

  2. 4

    Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, 12 K. Marks Str., Ufa, 450 000, Russia

Author Information

  1. 1

    Doshisha University, Kyotanabe, Japan

  2. 2

    Osaka City University, Osaka, Japan

Publication History

  1. Published Online: 28 JAN 2005
  2. Published Print: 25 FEB 2004

ISBN Information

Print ISBN: 9783527306596

Online ISBN: 9783527602469

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Keywords:

  • microstructure development;
  • copper single crystal;
  • equal channel angular pressing (ECAP);
  • ultra-fine grained materials;
  • dislocation density;
  • high angle grain boundary (HAGB);
  • electron microscopy

Summary

The equal-channel angular (ECA) pressing is most promising technique to produce ultra-fine grained (UFG) materials. Among the parameters of the ECA pressing, processing route, i.e., rotation of a billet around its axis between each pass, has been demonstrated to affect the microstructure development and grain refinement appreciably [1–4]. By the processing route, macroscopic shear plane can be controlled with respect to the texture and microstructure. Thus, it can be assumed that it is not accumulative strain (dislocation density) but an interaction between the shear plane and microstructures that governs the grain refinement [2]. In general sense, however, it is pointed out that during plastic deformation, a high angle grain boundary (HAGB) can be generated by the extension of a pre-existing boundary and/or generation by grain subdividing [5,6]. The former process is strain dependent and therefore high accumulative strain could result in grain refinement whereas the second is a consequence of the crystallographic nature of plastic deformation. ECA pressing can take advantage of the second process. In this context, examining the microstructural development in a single crystalline billet during ECA pressing provides us a deeper insight of (1) the role of pre-exist grain boundary on the grain refinement process by comparing with that of polycrystalline counterpart, (2) grain refinement mechanism from crystallographic viewpoint. In the previous study [7], we found that after eight passes via route C, the microstructure of single crystalline billet was still banded structure whereas that of a polycrystal was equiaxed UFG structure. In the current study, the effect of initial orientation on the grain refinement was examined. The role of interaction between macroscopic shear plane and shear bands was emphasized.