High Strain Rate Superplasticity in an Micrometer-Grained Al-Li Alloy Produced by Equal-Channel Angular Extrusion

  1. Prof. Dr. Michael Zehetbauer3 and
  2. Prof. Ruslan Z. Valiev4
  1. M.M. Myshlyaev1,2,
  2. M.M. Kamalov1 and
  3. M.M. Myshlyaeva1

Published Online: 28 JAN 2005

DOI: 10.1002/3527602461.ch13c

Nanomaterials by Severe Plastic Deformation

Nanomaterials by Severe Plastic Deformation

How to Cite

Myshlyaev, M.M., Kamalov, M.M. and Myshlyaeva, M.M. (2004) High Strain Rate Superplasticity in an Micrometer-Grained Al-Li Alloy Produced by Equal-Channel Angular Extrusion, 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.ch13c

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

    Institute of Solid State Physics, Russian Academy of Sciences, Chernogolovka, Russia

  2. 2

    Baikov Institute of Metallurgy and Material Science, Russian Academy of Sciences, Moscow, 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:

  • high strain rate superplasticity;
  • micrometer-grained materiel. Al-Li alloy;
  • equal-channel angular extrusion (ECAE)

Summary

Materials scientists, designers, and metal physicists have been showing recently acute interest in aluminum-lithium alloys due to the unique combination of their properties, namely, an increased elastic modulus, sufficiently high strength and low density. These features enable one to reduce appreciably the weight of space equipment with all concomitant advantages. Nowadays work is in progress aimed at improvement of properties of these alloys, also by forming in them nano- and microcrystalline structure via intensive plastic deformation. It is general knowledge that equal-channel angular extrusion (ECA-extrusion) is one of the most promising methods of achieving this goal. The following paper deals with precisely this method of forming a fine-grained structure.

The object of the study was the most advanced lightest (density 2.47 g cm−3) corrosion resistant weldable alloy Al–5.5%Mg–2.2%Li–0.12%Zr. When employed in welded constructions, it reduces the weight by 20–25 % and increases the rigidity by 6 %. It is superplastic and is widely used to fabricate workpieces of complex profile. Typical characteristics of its superplasticity (SP) are as follows: strain to failure is 350 % and the coefficient of strain rate sensitivity of stress is 0.45 at a strain rate of 5 ·10−3 s−1 at T = 480 °C [1].