Influence of citrate copper-plating electrolyte, its components and ultra-dispersed diamonds additives on surface properties of steel

Abstract

The state of the steel substrate (steel 3) was studied before the application of composite copper coatings from citrate copper-plating electrolyte. The properties of steel base in the investigated copper-plating electrolyte with the addition of ultradispersed diamonds (UDD) have been studied. A component-by-component analysis of the citrate copper-plating electrolyte was carried out, and the effect of each component on the properties of the steel electrode was evaluated. The possibility of using the considered electrolyte for coating directly on steel is shown, which significantly distinguishes it from currently used ethylenediamine, pyrophosphate, acid and other electrolytes. Electrochemical impedance spectroscopy and cathodic polarization were used as research methods. It was found that the lowest resistance of the steel surface (about 15 Ω) corresponded to the sample immersed in citrate copper-plating electrolyte with the addition of 1.0 g/l of UDD. Diffusion current density for suspensions with 1.0 g/l UDD in citrate copper-plating electrolyte was 2.6 A/dm 2 . Ultradispersed diamonds in citrate copper-plating electrolyte shielded the surface of the steel sample, while reducing the total resistance of the passive layer of steel 3. Equivalent electrical circuits of the surface of steel samples immersed in citrate copper-plating electrolyte and its components are also presented.