Dislocation Nodes in Face-Centred Cubic Lattices

Abstract

Two or more dislocation lines meeting at a point constitute a node. In face-centred cubic lattices a dislocation can split into two partial dislocations. The requirements of crystal geometry impose certain limitations on the arrangement of partial dislocations at a node. The various possibilities are discussed. It is shown that some nodes are fixed relative to the lattice, while others can move by glide processes in certain crystallographic directions. The length of dislocation line joining two nodes can function as a Frank-Read source. The effect of the node structure on the behaviour of the source is considered, and it is shown that such a source may progressively change its character during the process of dislocation production.