Interaction of Lomer-Cottrell locks with screw dislocations

Author(s)
Gunther Schöck
Abstract

In fcc crystals, dislocations are dissociated into partial dislocations and, therefore, restricted to move on lcub111rcub glide planes. By junction reactions with dislocations on two intersecting lcub111rcub planes, Lomer-Cottrell dislocations along ?110? directions can be formed which are barriers for approaching screw dislocations. Treating the interaction between a dissociated screw dislocation and a LC lock conventionally, using classical continuum theory and assuming the partials to be Volterra dislocations, leads to erroneous conclusions. A realistic result can only be obtained in the framework of the Peierls model, treating the partials as Peierls dislocations and explicitly taking account of the change in atomic misfit energy in the glide plane. At even moderate stresses (at less than 3 times 10-3 µ in Cu), the screw will combine with the LC lock to form a Hirth lock. As a result, the nature of the repulsive force will change drastically.

Organisation(s)
Physics of Nanostructured Materials
External organisation(s)
Universität Wien
Journal
Philosophical Magazine
Volume
90
Pages
629-636
No. of pages
8
ISSN
1478-6435
DOI
https://doi.org/10.1080/14786430903193274
Publication date
2010
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics
Portal url
https://ucris.univie.ac.at/portal/en/publications/interaction-of-lomercottrell-locks-with-screw-dislocations(ec609476-4571-4df3-b11d-27ccf5263e95).html