By Topic

Theory of the Thermal Breakaway of a Dislocation from a Row of Equally Spaced Pinning Points

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $31
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Blair, D.G. ; Royal Military College of Canada, Kingston, Ontario, Canada ; Hutchison, T.S. ; Rogers, D.H.

Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1063/1.1657110 

This paper gives a comprehensive description of the breakaway of a dislocation from a row of equally spaced pinning points, under the combined action of stress and temperature, within the model of Teutonico, Granato, and Lücke (TGL). The method is to obtain an algebraic solution, for a general pinning force, using, in turn, the continuous‐pinning approximation of TGL and the ``independent‐joint approximation''; the conditions of validity of these approximations are investigated in detail. For β«1, the pinning is effectively continuous; here, β=LcU0/Cr2, where Lc is the distance between pins, U0 is the maximum binding energy between a dislocation and a pin, C is the tension of the dislocation, and the pinning force has its maximum at a displacement of order r, the ``range.'' For β»1, the independent‐joint approximation holds (except near the mechanical breakaway stress). Then major breakaway (breakaway from the whole row) is activated at a single pin down to the stress σs = (4CU0/b2Lc3)1/2, where b is the Burgers vector. As the stress drops further, a saddle configuration still exists for breaking the first pin, but the dislocation must surmount higher saddle points to break subsequent pins. Major breakaway is activated over an increasing number of pins as the stress decreases, and for σ«σs the pinning becomes ``quasicontinuous.'' A paradox encountered by TGL is thus resolved.

Published in:

Journal of Applied Physics  (Volume:40 ,  Issue: 1 )