HRTEM Investigations of Amorphous and Nanocrystalline NiTi Alloys Processed by HPT

  1. Prof. Dr. Michael Zehetbauer2 and
  2. Prof. Ruslan Z. Valiev3
  1. T. Waitz1,
  2. H. P. Karnthaler1 and
  3. R. Z. Valiev3

Published Online: 28 JAN 2005

DOI: 10.1002/3527602461.ch6c

Nanomaterials by Severe Plastic Deformation

Nanomaterials by Severe Plastic Deformation

How to Cite

Waitz, T., Karnthaler, H. P. and Valiev, R. Z. (2004) HRTEM Investigations of Amorphous and Nanocrystalline NiTi Alloys Processed by HPT, 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.ch6c

Editor Information

  1. 2

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

  2. 3

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

Author Information

  1. 1

    Institute of Materials Physics, University of Vienna, Vienna, Austria

  2. 3

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

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:

  • amorphous NiTi alloys;
  • nanocrystalline NiTi alloys;
  • electron microscopy;
  • severe plastic deformation;
  • high pressure torsion (HPT);
  • transmission electron microscopy (TEM);
  • high resolution transmission electron microscopy (HRTEM)

Summary

In the intermetallic compound NiTi, functional thermomechanical properties, such as the shape memory effect and superelasticity are related to a martensitic phase transformation which is of considerable interest from both a scientific and a technological point of view. In addition, in NiTi amorphization can be induced applying various solid state processes such as particle irradiation [1], strong mechanical deformation by cold rolling [2] or mechanical alloying [3]. Severe plastic deformation by high pressure torsion (HPT) methods can be used to obtain almost complete amorphization [4].

It is the purpose of the present paper to apply different levels of strain (by HPT) to investigate the microstructural changes of bulk NiTi during the amorphization with transmission electron microscopy (TEM) methods including those of atomic resolution using high resolution transmission electron microscopy (HRTEM).