The extent of easy glide

A discussion is given of the well-known view that the end of easy glide, in FCC metals and solid-solution alloy crystals under tensile stress, is 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 is the increase in resolved applied stress on a secondary system, due to the lattice rotation caused by the easy glide; it is aided by internal stresses from the obstructed dislocations and also by thermal fluctuation stresses, but is opposed by friction stress from solute atoms in the alloy.