Dislocation motion in two-dimensional periodic fields

Abstract

The motion of a glide dislocation in two-dimensional periodic fields is discussed on the basis of the string model. It has been found that, if the variation in the internal stress is described by cosine functions, the macroscopic critical resolved shear stress determined by the motion of the most stable dislocation in the absence of thermal activation becomes equal to the maximum value of the internal stress along the direction of the dislocation motion. Consideration of the thermal activation process revealed that a double kink, similar to that in a one-dimensional periodic field, also exists in a two-dimensional field and that the activation volume and activation energy become essentially the same as those in the one-dimensional field.