A discussion was given of the well-known view that the end of easy glide, in face-centered cubic metals and solid-solution alloy crystals under tensile stress, was brought about by the activation of dislocation sources of secondary systems, which then provide forest obstacles to the glide dislocations of the primary system. The main factor bringing this about was the increase in resolved applied stress on a secondary system, due to the lattice rotation caused by the easy glide; it was aided by internal stresses from the obstructed dislocations and also by thermal fluctuation stresses, but was opposed by friction stress from solute atoms in the alloy.

The Extent of Easy Glide. A.Cottrell: Philosophical Magazine Letters, 2010, 90[2], 77-81