Polarization Phenomena during Zn-Ni-Fe Alloy Electrodeposition in Acidic Chloride Bath

摘要

The cathodic polarization of ternary Zn-Ni-Fe alloy deposition was studied under similar electrolysis conditions in comparison with Zn-Ni alloy deposition, in order to evaluate the effects of iron codeposition during the electrodeposition process. It was found that the Zn-Ni-Fe alloy deposition proceeds like an anomalous type of Zn-Ni deposition mechanisms, and the transition from normal to anomalous codeposition was observed at low critical current densities. The transition critical current density is not significantly changed by addition of a small amount of FeCl_2 (0.6 kmol/m~3) to the Zn-Ni bath. The deposition potential of Zn-Ni-Fe alloy is shifted to more negative values in comparison with Zn-Ni alloy deposition due to inhibitor effect of Fe codeposition.