Corrosion resistance of Zn-Al-Mg-La-Ce coatings by electric arc spraying

Zn-Al-Mg-La-Ce coatings were prepared by electric arc spraying, and their corrosion behavior was studied with salt spray test. The characteristics of the coatings before and after corrosion were investigated by energy dispersive spectrometry (EDS), X-ray diffraction (XRD), scanning electron microscopy (SEM), polarization curves, and electrochemical impedance spectroscopy. It is shown that the coatings have outstanding self-sealing effectiveness, and their structures are compact. During corrosion, microscopic pores on the surfaces of the coatings can be jammed with their own corrosion products, thus forming a dense corrosion product layer to prevent from further corrosion. Consequently, the corrosion resistance of Zn-Al-Mg-La-Ce coatings is superior to that of normal coatings.