Electrodeposition of Tin–Nickel Alloys from Ammonium Oxalate Electrolytes

The electrodeposition of tin–nickel alloys on steel 08kp from ammonium oxalate electrolytes and the physicochemical properties of the coatings were studied. It is shown that the electrodeposition proceeds with high polarization, in contrast to the deposition of tin–nickel alloys from the chloride–fluoride electrolyte. The highest corrosion rate (26 μA/cm²) was observed for the sample with a coating obtained from the chloride-fluoride electrolyte. Low corrosion rate was noted for the samples with coatings of tin–nickel alloys with low nickel contents, deposited from ammonium oxalate electrolytes with an addition of the OS-20 preparation (1.2–5 μA/cm²). The ratio of alloy components is shown to affect the chemical composition and microstructure of the coatings.