Description:
AbstractIn order to verify notions about the nature of the stage behaviour in KCl crystals the influence of purity and dimensions of KCl crystals on the stage behaviour of the workhardening curve τ(ϵ) has been studied.It is shown that in soft KCl crystals up to six stages of work hardening are observed. With increasing rigidity and decreasing sample dimensions (less than 2 mm2 cross section) the number of observable stages is reduced to three. As work hardening builds up the extent of odd stages (I, III, V) grows and that of even stages (II, IV) falls. The dependence of 1/γ on strain ϵ (γ‐activation “volume” of dislocation motion) for all the crystals studied is shown to replicate the τ(ϵ) curve. The rule of increasing the linear density of thermally surmountable obstacles on dislocations is the same for every pair of stages. This indicates that the nature of stages III and V is the same and caused by the activity of new slip systems oblique to the primarily active in stages II and IV, respectively.