Effect of Saccharin on the Process and Properties of Nickel Electrodeposition from Sulfate Electrolyte

Abstract

The effect of saccharin on surface morphology, hardness, internal stress of nickel deposit, cathodic current efficiency, throwing power, and cathodic polarization behaviors of plating solution during nickel electrodeposition from sulfate electrolyte are studied systematically. SEM images show that the grain size of nickel deposits can be greatly refined by adding saccharin in sulfate electrolyte. XRD, microhardness, and internal stress tests reveals that the addition of saccharin does not change preferential orientation of (200) plane but dramatically decreases the relative texture coefficient of (200) plane, increases the hardness of nickel deposits, and changes the internal stress of nickel deposits from tensile stress to compressive stress. Electrochemical test results demonstrate that the addition of saccharin has a minor effect on cathodic current efficiency but decreases the throwing power of plating solution and increases the cathodic overpotential.