Local dislocation reactions, self-organization and hardening in single slip

In fcc metals deformed in single slip, microstructures are dominated by dipolar and multipolar features forming bundles that exhibit profuse evidence of annihilation events and reactions between primary and cross-slipped segments. Dipolar annihilation is manifested in strings of near-edge prismatic loops whose arrangement depends on the relative velocities of the approaching parent dislocations. Supporting this, dislocation dynamics simulations reveal the influence of the relative positions of the sources, their characters and their lengths. Molecular dynamics simulations show that narrow dipoles undergo complex transformations yielding a variety of debris whose atomic structure depends on composition, temperature and dipole height. In the simulations, the debris do not disappear.