Abstract

Two mechanisms of the formation of antiphase-boundary tubes resulting from the shortening of Kear-Wilsdorf locks are examined in the light of a recent paper by Chiu and Veyssie ¤ re. The mechanism based on bypassing KW locks and subsequent annihilation of the screw dipole by cross-slip is considered in more detail. It is concluded that the objections raised by Chiu and Veyssie ¤ re against this mechanism are not valid, and that the predictions of the mechanism are consistent with their experimental observations. Questions are raised as to whether some of their observations are inconsistent with the operation of the mechanism based on the motion of jogs whose corners are relaxed by forced climb