It was noted that the poly-twin interfaces frequently present in L10-phases after suitable heat treatment strongly influenced the properties and behavior of this class of intermetallic. The interactions of dislocation glide and twinning, with poly-twin interfaces, was studied via crystallographic and geometric analyses of {101}-conjugated poly-twin L10-phases. The most suitable boundary reactions for the shear transfer of hard dislocation glide and micro-twinning across {101}-conjugated poly-twin interfaces in L10-phases were determined. Defect/interface interactions in lightly-deformed poly-twin FePd, which exhibited {101}-conjugated poly-twin interfaces, were documented by making experimental observations using transmission electron microscopy. A model for the defect-interface interactions in poly-twin FePd, based upon the most suitable boundary reactions identified by theoretical analyses, was proposed and was found to be consistent with the experimental transmission electron microscopic observations. This model permitted a micro-mechanism based rationalization to be made of the plastic flow behavior which was typical of polycrystalline poly-twin FePd.

Dislocation and Twin Interactions with Polytwin Interfaces in L10-Ordered FePd. J.M.K.Wiezorek: Intermetallics, 2003, 11[1], 9-21