Core structure of nonscrew1/2(111) dislocations on (110) planes in b.c.c. crystals. II. Peierls stress and the effect of an external shear stress on the cores

Abstract

For pt. I. see ibid., 523-36. The Peierls stress of the ¹/₂(111) nonscrew dislocations was calculated. Two methods were used: positioning the dislocation in various crystallographically nonequivalent positions and calculating the corresponding variation in its core energy, and simulation of the dislocations in a crystallite subject to an applied shear stress. In the latter case the changes of the core under the external stress were followed. Both methods give similar results which suggests that the changes in the core are not of great importance. Comparison with the screw dislocations and possible implications of the results for the plastic behaviour of b.c.c. metals are then briefly discussed.