Electron diffraction study on iron-zinc Γ1 intermetallic phase in a galvannealed IF steel sheet

A series map of selected area electron diffraction patterns(SADPs) of Γ1 phase in commercial galvannealed IF steel sheet were investigated by transmission electron microscopy(TEM). The cross-sectional TEM specimen was prepared using focused ion beam (FIB) technique which was also introduced briefly. The results show that there exist superlattice reflections in the SADPs of Γ1 phase which indicate that Γ1 phase is a kind of ordered intermetallic compound with twice times period. It is different from the six times period structure of Γ1 single phase specimen which was prepared by special method.