The criterion of anomalous slip at 0 K in body centered cubic metals

It is generally accepted that anomalous slip (AS) takes place by hexagonal dislocation networks (HDNs) in body centered cubic (BCC) metals, but the role of the HDN formation process in AS has rarely been investigated so far. In this work, the critical yield conditions of the HDNs and isolated dislocations were first calculated, respectively, by molecular statics simulations in two BCC metals. Based on these data, a novel mechanism, entitled as the “conjugated dislocation sources” (CDS), to analyze the formation of the HDNs was proposed for the first time and then incorporated into the criterion of the occurrence of AS. Our prediction is in agreement with experimental observations. Contrary to previous study, it has been revealed that the multiplication of isolated screw dislocations involved in AS has to be considered for correctly understanding the AS origin.