Many efforts have been made to develop highly corrosion-resistant steel sheets, especially for automotive body panels. Recently, it has been shown that elec-trodeposited zinc-iron group metal alloys are suitable materials for this application. A major development in this area has been directed toward zinc-nickel (8-20) alloy coatings because of a higher degree of corrosion resistance and better mechanical properties than a pure zinc layer. In the present work, binary Zn-Ni and ternary Zn-Ni-Fe alloy coatings were obtained on mild steel by electroplating in a chloride bath. In order to make a clear comparison between Zn-Ni and Zn-Ni-Fe alloys for micro-hardness, crystal structure, and grain size, the ternary deposits were obtained at similar operating conditions to the binary alloy.
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