Grain Refinement and Texture Formation during High-Strain Torsion of NiAl

  1. Prof. Dr. Michael Zehetbauer4 and
  2. Prof. Ruslan Z. Valiev5
  1. W. Skrotzki1,
  2. B. Klöden1,
  3. R. Tamm1,
  4. C.-G. Oertel1,
  5. L. Wcislak2 and
  6. E. Rybacki3

Published Online: 28 JAN 2005

DOI: 10.1002/3527602461.ch5c

Nanomaterials by Severe Plastic Deformation

Nanomaterials by Severe Plastic Deformation

How to Cite

Skrotzki, W., Klöden, B., Tamm, R., Oertel, C.-G., Wcislak, L. and Rybacki, E. (2004) Grain Refinement and Texture Formation during High-Strain Torsion of NiAl, 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.ch5c

Editor Information

  1. 4

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

  2. 5

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

Author Information

  1. 1

    Institut für Strukturphysik, Technische Universität Dresden, Dresden, Germany

  2. 2

    HASYLAB at DESY, Hamburg, Germany

  3. 3

    Geoforschungszentrum Potsdam, Potsdam, Germany

Publication History

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

ISBN Information

Print ISBN: 9783527306596

Online ISBN: 9783527602469

SEARCH

Keywords:

  • grain refinement;
  • texture formation;
  • high-strain torsion;
  • NiAl;
  • measurement;
  • electron back-scatter diffraction (EBSD);
  • scanning electron microscope (SEM);
  • high-energy synchrotron radiation

Summary

The intermetallic compound NiAl has special properties, like high melting point, low density, good corrosion resistance and moderate creep strength, making this material interesting for high-temperature applications. However, a widespread acceptance as structural material was hindered so far by the inadequate low-temperature toughness and ductility. Attempts to increase the ductility of NiAl by alloying have not been successful [1]. Another way to approach this problem is by changing the grain structure and texture on purpose. As the yield stress increases much slower with decreasing grain size than the fracture stress, grain refinement should help to reach the ductile field (Fig. 1) [2]. This field can be extended by changing the texture in such a way that the Taylor factor is reduced. Thus, in order to optimize the desired mechanical properties by thermomechanical treatment it is of particular interest to understand the mechanism of grain structure and texture formation during deformation and annealing. Therefore, it was the aim of the present work to strongly deform NiAl polycrystals in torsion, a deformation mode allowing the study of microstructure and texture with strain. To do this, methods with high spatial resolution had to be used which are given by electron back-scatter diffraction (EBSD) in the scanning electron microscope (SEM) and by texture measurements with high-energy synchrotron radiation.