The interaction between extended dislocations and antiphase domain boundaries - II: uncoupled superpartial dislocations and planar slip

Due to their interactions with antiphase domain boundaries, superdislocatio ns can move effectively as uncoupled superpartial dislocations in ordered s tructures. It is shown that there is a critical domain size below which thi s will occur irrespective of the grain size and APE energy. Our analysis al so indicates that, because of superdislocation/domain boundary interactions , the stress required to move a superdislocation on a 'fresh' slip plane is maximum. Once superdislocations glide over a slip plane, an increasingly e asy slip channel is created for the following superdislocations gliding on the same plane. Therefore, planar slip is expected. The smaller the APD siz e, the more likely is planar slip. (C) 2001 Elsevier Science Ltd. All right s reserved.