چكيده به لاتين
Aluminum Alloys have a high affinity to react with oxygen, and then rapidly oxidize in the molten state. Oxidation in the molten state divides into static and dynamic categories. Bifilm which formed as a result of dynamic oxidation will often act as a crack or cavity in the finAl part. Recently, the study of the characteristics, formation mechanism and heAling of the Bifilms, have attracted many researchers. The oxide/metAl/oxide sandwich method is one of the best ways for study the dynamic oxidation of the melts. Air bubbles with 0.8-atmosphere pressure were blown into the melts, and then the intersection of the entrapped bubbles was considered as the oxide/metAl/oxide sandwiches. The characteristics of the Aluminum oxide films and effect of adding different amounts of zinc (3, 5, and 7 weight percent) on them, including their morphology and thickness, were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). There was no significant difference in the morphology of the oxide films. However, by adding zinc, the location of stress concentration and more cracks were found on the oxide film. The thickness of the oxide films for the Aluminum Alloys was estimated from 95 nm to 1070 nm. By adding zinc to Aluminum up to 3% wt, the thickness of the oxide film increased. While adding more than 3% wt zinc, decreased the thickness of the films. Reducing the thickness of oxide films indicates an increase in oxidation resistance in Aluminum-zinc Alloys
