Screw dislocation core structure and plastic deformation of BCC Metals

Abstract

Abstract The core structure and an energy distribution around a screw dislocation core in model bcc lattice have been investigated in both unstressed and stressed states to clarify the controlling factors which determines the core type and the shape of P EIERLS potential. In the case of iron total four types of core structure were obtained, namely, unpolarized, polarized, split and high energy position and the shape of P EIERLS potential was so‐called camel hump type which gives a steadfast explanation for the presence of a hump on the yield stress — temperature curve of iron single crystal. The calculated results for the spatial distribution of the P EIERLS potential around a core show that the range of distribution is relatively small in the low P EIERLS stress case (iron), but is large in high P EIERLS stress case (vanadium).