Influence of the Thermal Anisotropy Internal Stresses on Low Temperature Mechanical Behavior of Polycrystalline and Nanostructured Ti

  1. Prof. Dr. Michael Zehetbauer2 and
  2. Prof. Ruslan Z. Valiev3
  1. V.Z. Bengus and
  2. S. N. Smirnov

Published Online: 28 JAN 2005

DOI: 10.1002/3527602461.ch3g

Nanomaterials by Severe Plastic Deformation

Nanomaterials by Severe Plastic Deformation

How to Cite

Bengus, V.Z. and Smirnov, S. N. (2005) Influence of the Thermal Anisotropy Internal Stresses on Low Temperature Mechanical Behavior of Polycrystalline and Nanostructured Ti, 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.ch3g

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. B. Verkin Inst. for Low Temperature Physics & Engineering, Ukraine Academy of Sciences, Kharkov, Ukraine

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:

  • severe plastic deformation (SPD);
  • thermal anisotropy internal stresses;
  • low temperature mechanical behavior;
  • polycrystalline titanium;
  • nanostructured titanium;
  • microstructural thermal anisotropy stresses (MTAS)

Summary

In polycrystalline non-cubic materials temperature variations can cause internal thermoelastic microstresses due to the anisotropy of the thermal expansion coefficient in individual grains. These stresses were called [1] microstructural thermal anisotropy stresses (MTAS). If the MTAS exceed the critical stress at which slip (or twinning) starts in any of the crystallographic systems of plastic shear in an individual grain, this grain experiences plastic deformation. This really occurs on heating, cooling and thermocycling of soft polycrystalline metals. The phenomenon was first detected by Boas and Honeycombe in the 1944-47ies [2], who tried to estimate roughly the order of MTAS magnitude. V.A. Likhatchev obtained formulae for the order of magnitude calculation of MTAS in polycrystals of all non-cubic symmetries. He used the model of an elastically and thermally anisotropic grain immersed into isotropic medium [1]. We employ Likhatchev's model to calculate the MTAS in the grains of coarse- and ultrafine grain (nanostructured) titanium on cooling below room temperature. The MTAS effect on the mechanical behavior of titanium is estimated.