An evaluation of rate-controlling obstacles for low-temperature deformation of zirconium

Sastry, DH and Prasad, YVRK and Vasu, KI (1971) An evaluation of rate-controlling obstacles for low-temperature deformation of zirconium. In: Journal of Materials Science, 6 (4). pp. 332-341.

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Abstract

The low-temperature plastic flow of alpha-zirconium was studied by employing constantrate tensile tests and differential-stress creep experiments. The activation parameters, enthalpy and area, have been obtained as a function of stress for pure, as well as commercial zirconium. The activation area is independent of grain size and purity and falls to about 9b2 at high stresses. The deformation mechanism below about 700° K is found to be controlled by a single thermally activated process, and not a two-stage activation mechanism. Several dislocation mechanisms are examined and it is concluded that overcoming the Peierls energy humps by the formation of kink pairs in a length of dislocation is the rate-controlling mechanism. The total energy needed to nucleate a double kink is about 0.8 eV in pure zirconium and 1 eV in commercial zirconium

Item Type:	Journal Article
Publication:	Journal of Materials Science
Publisher:	Springer
Additional Information:	Copyright of this article belongs to Springer.
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	16 Jul 2010 08:39
Last Modified:	19 Sep 2010 06:09
URI:	http://eprints.iisc.ac.in/id/eprint/28522

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