The effect of solid-solution H upon the edge or screw character of dislocations was investigated by deforming samples of high-purity material in situ in a gaseous H environment within a controlled-environment transmission electron microscope. The solute H was found to stabilize edge segments of dislocations. This inhibited, and sometimes stopped, dislocations from cross-slipping. The removal of H from the sample permitted the cross-slip process to continue. These results provided an explanation for the macroscopic observation that H in solid solution could promote slip planarity.

Hydrogen Effects on the Character of Dislocations in High-Purity Aluminium. P.J.Ferreira, I.M.Robertson, H.K.Birnbaum: Acta Materialia, 1999, 47[10], 2991-8