The effect of plastic deformation mode upon the recrystallization behaviour of copper-cobalt crystals

Abstract

Two-phase copper—cobalt crystals have been prepared and plastically deformed 1. (a) in tension using crystals of initial single- and double-slip orientations, and 2. (b) by cross-rolling up to 30 per cent R.A. These were subsequently annealed above the particle solvus temperature, and the kinetics of recrystallization were determined—the structural changes being followed by transmission electron microscopy. It is shown that the ease of reorystallization is associated with appreciable non-uniform secondary (e.g. cross and conjugate) slip resulting from unequally stressed slip systems. Recrystallization only occurs after high strains associated with decreasing rates of work hardening. Only alloys deformed to lower strains than these annealed to inherently stable recovered dislocation arrays. In all cases significant dislocation rearrangement occurred prior to recrystallization. Thus in technological processing operations, particle-pinning is necessary to provide the principal source of recrystallization resistance if a high stored energy is required.