Electrochemical copper plating on steel from the electrolyte containing iron(II) ions and tin dioxide sol

Abstract

It is shown that copper plating on the polished steel from diphosphate electrolyte is accompanied by iron oxide film dissolution followed by iron(II) reduction together with copper. The effect of Fe2+ ions on the properties of copper coatings obtained from diphosphate electrolyte containing SnO2 sol and in its absence has been studied. The addition of SnO2 sol into the electrolyte provides ten times increase in the protective ability of coatings deposited at current density of 1 А/dm2. To achieve the same effect in case of the electrolyte containing accumulated iron ions it is necessary to diminish current density up to 0.5 А/dm2. Copper coatings deposited in the presence of SnO2 sol and accumulated Fe(II) have fine-grained dense microstructure and a microhardness 20 % higher than coatings plated in the absence of the additives.

Keywords

• copper plating
• diphosphate electrolyte
• tin dioxide sol
• iron(ii) ions
• steel
• corrosion