Analysis of the amplitude dependent damping data in terms of the Granato--Lucke model

Journal Article · Thu Jan 01 04:00:00 EST 1976 · Scr. Metall.; (United States)

DOI:https://doi.org/10.1016/0036-9748(76)90151-4· OSTI ID:7365494

Atrens, A; Ritchie, I G

The data of Atrens (Scripta Met., 8: 401(1974)) is consistent with the Granato--Lucke model, and a binding energy in the range 0.1 to 0.2 eV is obtained. A value of the binding energy, U/sub B/ approximately 0.1 to 0.2 eV is not, however, consistent with estimates obtained from theories of thermally assisted unpinning, in which a dislocation unpinning peak is expected at a temperature T defined by U/sub B/ = kT ln (..nu../..omega..) where ..nu.. is the attack frequency of the dislocation (..nu.. approximately 10/sup 13/ Hz for zirconium) and ..omega.. is the frequency of the applied stress. For a dislocation breakaway peak to pass through the experimental strain range of the data reported by Atrens at a temperature of the order of 300/sup 0/C, the above equation predicts U/sub B/ approximately 1.5 eV. This possibility of thermally assisted unpinning leads to much greater uncertainty concerning the estimations of U/sub B/ than the relatively minor corrections to the Granato--Lucke theory. In addition, it is important to note that the theoretical treatment of thermally assisted dislocation breakaway would indicate that a Granato--Lucke plot provides no experimental basis for distinguishing between the zero temperature theory or the high temperature theory.

• Research Organization: Atomic Energy of Canada, Ltd., Pinawa, Manitoba
• OSTI ID: 7365494
• Journal Information: Scr. Metall.; (United States), Journal Name: Scr. Metall.; (United States) Vol. 10:2; ISSN SCRMB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
AMPLITUDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DAMPING
DISLOCATIONS
ELEMENTS
FRICTION
INTERNAL FRICTION
LINE DEFECTS
MAGNETIC FLUX
METALS