Abstract
The concentration and strain rate dependence of the critical shear stress in KCl–KBr solid solutions was measured by compression tests. These data were compared with the stress dependence of the dislocation velocity measured by an etch pit technique. Edge dislocation moved slower than screw dislocation at the same stress level. The critical stress was determined by the edge dislocation mobility, and the mobile dislocation density at yielding was about 1.2×1011 m-2 for the three kinds of composition tested. An analytical model of the hardening mechanism is proposed on the basis of the elastic interaction (size misfit) between an edge dislocation and solute atoms. When compared with experimental results, this model gives satisfactory results not only for KCl–KBr but also for NaCl–NaBr, and NaBr–KBr solid solutions.