The anomalous slip in body-centered cubic metal crystals, which was clear violation of Schmid’s law, was shown to be a natural result of the fact that the slip planes of a/2<111> screw dislocations changed from {110} at low temperatures to {112} at higher temperatures. Above the temperature for this change, which was responsible for the so-called lower bend in the flow-stress versus temperature relationship, the 2 slip systems with the largest resolved shear stresses had different slip directions. The screw dislocations of these systems could avoid jog formation and the generation of atomic defects by cross-slipping onto the anomalous {110} plane. This accounted for the dependence of anomalous slip upon temperature, crystallographic orientation and purity. The variation from metal to metal was shown to be related to the elastic anisotropy. Mechanisms that might be responsible for the absence of anomalous slip from body-centered cubic Fe were considered.

Anomalous Slip - a Feature of High-Purity Body-Centered Cubic Metals. A.Seeger, W.Wasserbäch: Physica Status Solidi A, 2002, 189[1], 27-50