In the current work, nanostructured Zn-Ni alloys are electrodeposited by direct and pulse current from alkaline sulfate electrolytes in the presence of additives and complexing agents. The ratio of the zinc and nickel was effectively controlled by varying the concentration of the electroactive species and operating parameters. The new electrodeposited Zn-Ni alloy has an increased content of nickel as compared to the conventional Zn-Ni alloy. The increase in the nickel content accounts for the decreased corrosion potential of the Zn-Ni coatings. The corrosion potential of the Zn-Ni alloy is -0.702 V (vs. SCE), which is still electronegative when compared to steel and offers sacrificial protection to steel. The coatings have superior corrosion resistance and barrier properties when compared to conventional Zn-Ni and cadmium coatings. Polarization studies on nanostructured Zn-Ni coatings show a barrier resistance that is higher than the conventional Zn-Ni coatings by an order of magnitude. The compositions of the coatings were analyzed by EDX. The surface morphology of the coatings was studied using SEM (Scanning Electron Microscope). Improved corrosion and hydrogen inhibition properties make it a potential alternative for the cadmium coatings.
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