General yield behaviors of the {110} hexagonal dislocation networks in body centered cubic metal molybdenum

摘要

The {110} hexagonal dislocation networks (HDNs) act as important carriers of the low-temperature plastic deformation in the body-centered-cubic (BCC) metals. Erenow, only a handful of studies have been performed on the yield behaviors of this planar networks, resulting in it being perplexing. In this letter, by three types of loading modes, the general yield behaviors, which comprise the critical stresses to move the network along any direction on the (01 (1) over bar) plane, the partitions on the cooperative motion of two or three sets of dislocations and the conditions under which the steady motion of the HDN takes place, are proposed to disclose the motion mechanism for the HDNs in molybdenum by atomistic simulations. Also, the characteristic that the motion directions of the HDN are changeable, a result of the natural transition to the steady motion, explains why there is no fixed dead band for the (01 (1) over bar) anomalous slip in these BCC metals.