A general dislocation model for high-temperature creep

Abstract

A 'unified' theory of high-temperature creep of pure metals is described. It assumes that the thermally activated glide velocity of slip dislocations is determined by (a) the dynamic equilibrium spacing of local jog obstacles and (b) the value of the long-range back stress resulting from a balance between strain hardening and climb-controlled recovery. At low strain rates the flow stress is almost entirely of long-range origin and the model reduces to the form of conventional recovery theory. At high strain rates local obstacles become increasingly important, in accordance with recent experimental observations.