Electrodeposition of CuSn Alloy from Noncyanide Sulfosuccinate Bath

Abstract

Recently the regulation of nickel usage because of allergy issues has been strengthened in Europe and other countries. The Cu-Sn alloy (40-55 mass%Sn) is called “speculum alloy” or “white bronze” and has a silvery-white appearance. We developed a noncyanide Cu-Sn alloy plating bath consisting of sulfosuccinic acid, L-methionine and polyoxyethylene-α-naphthol, from which silvery-white Cu-Sn alloy (40-55mass%Sn) were obtained. It is anticipated that the Cu-Sn alloy films will be used as an alternative to nickel undercoating for decorative gold or chromium electroplating.

Corrosion Resistance Properties of Cu-Sn Electrodeposited from a Cyanide-Free Bath

“…Herein, we demonstrate that we can obtain a fine and smooth Cu-40%Sn alloy using a process with high electric-current efficiency (75%-90%) and that the obtained alloy has a component ratio comparable to that of the plating bath. Moreover, the alloy composition is only weakly dependent on current density over a wide range of current densities (0.5-4 A/dm 2 ), and the color of the obtained alloy film is silver-white, similar to that of plated Ni (5).…”