Abstract
Various compositions of zinc-iron alloy deposits were obtained from the sulfate bath containing ZnSO4, FeSO4, NH4Cl, and Al2 (SO4)3.
The compositions of these alloy deposits depended upon bath composition, pH, temperature, and current density. The iron contents of these deposits were generally increased with increase of iron concentration in the bath and drop of bath temperature as well as increase of current density and pH value. The iron contents of the alloys were lower than those in the baths, particularly in the baths of lower concentrations of iron. However, alloye of higher iron contents were deposited from the baths containing iron of about 70% or more. Other addition agents in the bath had little effects on the alloy compositions.
Corrosion resistance of these deposit was confirmed by salt spray test and it was found that 2.5% iron alloy had the highest resistance to white rust. The resistance of the deposits was remarkably lower when the iron content was more or less than 2.5%. It was observed that the possibility of the formation of white or red rust was higher in the deposits of higher iron contents.
