The Action Mechanism Of Potassium Chloride Zinc Plating Additive

In recent years, a lot of work has been done in the field of potassium chloride zinc plating in China, and the quality of potassium chloride zinc plating additives has also reached a high level.
In potassium chloride zinc plating solution, the standard reaction rate constant for zinc ion reduction is relatively large, indicating that it is impossible to obtain a qualified zinc coating in potassium chloride zinc plating solution without additives. Among the various organic compounds added, non ionic or anionic surfactants containing ethoxyl or propioxy groups have a significant inhibitory effect on electron transfer reactions, which can increase the polarization of the metal deposition process, resulting in small grains, excellent dispersion ability, and deep plating ability.
Moreover, the polymerization degree, hydrophobicity, and type of various organic compounds in potassium chloride zinc plating additives have completely similar effects, with polarization values only differing by a few tens of millivolts. Compared with the total polarization value of 450mV, the change is very small. Therefore, OP, Pingpingjia, polyethylene glycol, polyoxypropylene ether and its sulfonates, and polyol non ionic surfactants can all be the main components (carriers) of potassium chloride zinc plating additives.
A black film can be observed during the pickling and removal of the zinc coating, and the color of the film deepens with the increase of the amount of potassium chloride zinc plating additive; The retreating solution gradually produces a foam layer that is not easy to dissipate, which indicates that non-ionic surfactants are mixed in the zinc coating and cause consumption.