Why anomalous slip in body-centred cubic metals?

Anomalous slip in high-purity bcc metals (=slip on a {110} plane with small resolved shear stress) is shown to be a natural consequence of the fact that above the ‘lower bend’ in the flow-stress–temperature relationship the elementary slip steps of the strain-rate determining 〈111〉a0/2 screw dislocations proceed on {112} planes. A brief comparison experiment–theory indicates that the proposed mechanism accounts for the major experimental findings.