Motion of dislocations through a random array of weak obstacles

On the basis of the results of the preceding paper the thermally-activated motion of zigzag dislocations is described in terms of a mobility. The latter can be defined by introducing the frictional force due to the interaction drag mechanism. The mobilities for the three cases of repulsive, attractive and mixed interaction are calculated. It is shown that the damping curves produced in periodic stress experiments can be excellently approximated by a simple Debye peak. Some applications of zigzag dislocations in the theory of plastic deformation are discussed.