Corrosion resistance and mechanical properties of zinc electrocoatings

Zinc electrocoatings obtained from an industrial bath were characterized by analyzing properties such as morphology, structure, microhardness and residual stress. The influence of plating variables (additives, current density, deposit thickness) on these properties was also studied. The corrosion behaviour of the deposits was analyzed by salt-spray and electrochemical methods and a good correlation between the results obtained with both techniques was observed. For all properties studied, the most influential parameter was the presence of a tensioactive used as an additive in the plating bath, and a relationship was established between some of the coating characteristics and the corrosion resistance. (C) 1997 Elsevier Science Ltd.