Computer simulation of the screw dislocation motion in b. c. c. metals under the effect of the external shear and uniaxial stresses

Abstract

An atomistic study of the motion of the 1/2 [111] screw dislocation was carried out for a shear stress applied on {112} planes and for uniaxial stresses along [012], [001] and [111]. Central force interactions described by the three different empirical potentials used in the previous work (Duesbery, Vitek & Bowen 1973) were assumed. The distortions of the core and the subsequent dislocation motion always reflected the twinning-antitwinning asymmetry of shear on {112} planes. The non-shear components of the stress tensor introduced further asymmetries which vary with interatomic forces. The application of the results of this study to the theory of slip and twinning in b. c. c. metals, is discussed.