Computer simulation of motion of screw dislocation in model B.C.C. lattices. II. Orientation dependence of slip

To understand the mechanism of the plastic anisotropy in b.c.c. metals at low temperatures, motion of screw dislocation under stress at 0 °K for various orientations has been computer-simulated using model b.c.c. lattices having systematically varied inter-atom-row potentials. Below the Peierls stress, several types of transitions of the core structure took place. As a result, dislocation motion was quite anisotropic and the orientation dependence of the Peierls stress did not obey Schmid's law. τp–χ and Ψ–χ relations obtained for some range of inter-atom-row potentials were in agreement with the observed results on refractory b.c.c. metals at low temperatures except the operative slip plane near χ = 30°.