A COMPARATIVE STUDY ON CHARACTERISTICS OF DYNAMIC OXIDE FILM OF MOLTEN Zn-Al ALLOYS

This paper investigates the difference between thickness of zinc-based alloys oxide films in dynamic condition using the oxide-metal-oxide (OMO) sandwich method and static condition by theoretical calculations. In dynamic condition, the thickness of the oxide film in the OMO sandwich sample was characterized by scanning electron microscopy (SEM). In the static condition, the thickness and type of the oxide films were studied based on thermodynamic and kinetic estimations. The results showed that the oxide film thickness in molten Zn4Al and ZA27 alloys using OMO sandwich method was estimated to be in the range of 70-200 nm and 30-100 nm, respectively. However, the thickness of oxide films in the static oxidation based on the theoretical calculations, regardless of melt chemical composition, were about 2-5 nm.