INFLUENCE OF INTERNAL STRESS FIELDS ON VELOCITY OF DISLOCATIONS

The influence of periodic internal stress fields of various types on the average dislocation velocity is investigated. An Arrhenius type equation is used to describe the dislocation velocity, and the calculations are carried out assuming that the activation volume is a) constant, and b) a function of the stress. It is shown that for almost any type of periodic field the average dislocation velocity can be expressed as a simple function of the ratio α = τ0/τa, where τ0 is the amplitude of the stress field and τa is the applied stress. The average value of the internal stress, or the hardening produced by the internal stress field, is not strictly athermal, although its temperature dependence is small. Both the temperature and stress dependence of the average dislocation velocity is influenced by the presence of internal stresses. However, this effect is small and can be neglected for most practical cases, especially at low temperatures. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim