Study on the mechanism of additives affecting corrosion resistance in zinc alloy plating

Abstract

In the plating process, the addition of additives can improve the quality of the plated layer. Suitable additives can make the plated layer more resistant to corrosion while obtaining a flat and bright plated layer. In this paper, the effects of four types of additives on the corrosion resistance of electroplated zinc–nickel alloy plating were investigated, and the process conditions such as current density and plating time were determined by Hull tank experiments and small tank experiments. The effects of the content of various additives and different additives on the corrosion resistance of the plating layer were investigated, and the optimal additives were the compound combination of BH-A and BH-B at 6 mL/L each. Under the same plating process conditions, the effect of adding suitable additives and not adding additives on the corrosion resistance of the plated layer was investigated. The findings revealed that, in comparison to the plating solution sans additives, the integration of appropriate additives not only enhanced the deposited layer’s corrosion resistance but also led to a decrease in grain size, increased uniformity, density, and achieved a higher degree of flatness. The results indicate that, in contrast to the plating solution without additives, the inclusion of suitable additives not only enhances the corrosion resistance of the resulting plated layer but also generates a smaller grain size, uniformity, density, and higher flatness in the deposited layer.