Occurrence of shear bands in the order-disordered FeCo-2V alloy

Abstract

Shear bands have been observed at about 35° to the rolling plane when the alloy was cold rolled to about 5 to 10% reduction. Although this alloy consists essentially of a bcc lattice in the disordered state, brought about by quenching, and of a CsCl type of lattice in the ordered state, the bands can similarly be obtained for both states. From TEM observations, the planes on which the bands may be formed seemed to be {011} and {112}, corresponding to the slip and twinning planes, respectively, of bcc metals and alloys. An attempt has been made to interpret the formation of the shear bands: since cross slip may be difficult to obtain in the alloy because of the existence of the superlattice, sites of stress concentrations are produced relatively easily, and these are relaxed by the localized shearing and formation of shear bands.