Zinc-Nickel alloy coatings electrodeposited by pulse current and their corrosion behavior

Steel in subtropical monsoon regions encounters severe atmospheric corrosion. In an attempt to provide better corrosion protection, zinc-nickel alloys were electrodeposited on steel by pulse current. Some electric variables (average current density and pulse cycle) and bath temperature on chemical compositions and grain size of coatings were studied. Next, zincnickel alloys electrodeposited on steel were prepared for atmospheric corrosion tests. In addition, the determination of the chemical compositions and the grain size of the Zn-Ni alloy coatings were conducted by scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS) and scanning probe atomic force microscope (AFM). Furthermore, Tafel plots were employed to evaluate the alloy corrosion behavior.