Aluminum and antimony segregation on a batch hot-dip galvanized Zn-0.05Al-0.2Sb coating
School of Engineering
Segregation of aluminum and antimony of spangles on a batch hot-dip galvanized Zn-0.05Al-0.2Sb coating were investigated by scanning electron microscopy (SEM) in backscattered electron mode and with energy dispersive spectrometry, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Results showed that the coating surface displays shiny, feathery and dull spangles, in which considerable metallic oxides and precipitates are detected on coating surface. The metallic oxides on coating surface are identified as mainly ZnO and Al2O3, whilst the nature of the precipitates is identified as Sb3Zn4. Aluminum and antimony are enriched in layers within a thickness of 10–20 nm underneath the outer surface of the coating. The segregation behavior of aluminum and antimony is studied and discussed in terms of the solidification process of the coating.