Organic additives in zinc electroplating

The use of organic additives in zinc electroplating is reviewed with particular emphasis on the types of compounds used, the bath type for which they are most suited, and their function with respect to brightening and levelling action. Fundamental studies of the mode of action of these additives are also reviewed and comparisons are made with similar studies of nickel and copper electrodeposition. It is concluded that much more fundamental studies are required to fully explain the effects of additives. Further, the effect of codeposition of organic impurities on the corrosion resistance of electrodeposited zinc requires urgent study.