Abstract
Atomistic studies of anisotropic mobility of hexagonal dislocation networks (HDNs) in a series of twist boundaries (1 -1 0) has been performed in alpha-iron. In contrast with previous work that neglected the twist angle effect, we find when the twist angle approaches to 0, the resistance to the HDN motion could become much lower than Peierls stress of edge dislocations <1 1 1>/2 when the HDN moves along [0 0 1], but beyond Peierls stress of screw dislocations <1 1 1>/2 when the HDN moves along other directions. Vector form of Orowan equation and differential displacement map of dislocation core are used to analyse the behaviour of these boundary dislocations. This work seems favourable for understanding the absence of anomalous slip in alpha-iron.
