PLASTIC ANISOTROPY IN BCC TRANSITION-METALS

Motion of a [111] screw dislocation in a b.c.c. crystal has been inves tigated in the concept of thermally activated kink pair formation. To explain the plastic anisotropy of b.c.c. transition metals, a two dime nsional Peierls potential is assumed in the (111) plane without specif ying the glide plane. Using the two dimensional Peierls potential, the critical flow stress and the direction of integrated slip plane have been calculated as a function of the direction of the applied stress a nd temperature. The calculation with a refined Peierls potential, whic h has hexagonal contours around the stable positions, successfully rep roduces quantitatively the plastic data of alpha-Fe. (C) 1997 Elsevier Science S.A.