Investigation of the elementary mechanisms controlling dislocation/twin boundary interactions in fcc metals and alloys: from conventional to advanced TEM characterization

The elementary mechanisms controlling the interactions between lattice gliding dislocations and twin boundaries were carefully analyzed using conventional and advanced transmission electron microscopy techniques in both bulk coarsegrained Fe-Mn-C TWIP steels with deformation twins and nanocrystalline Palladium thin films with nanoscale growth twins. The results reveal that the individual dislocation/TB reactions depend mainly on the stacking fault energy of the material as well as the nature of the incoming dislocations nucleated during the plastic deformation of the material. It is also demonstrated that such investigation requires dedicated and specific microscopic techniques depending on the microstructure and the intrinsic properties of the crystallographic defects of the materials.