The effect of texture on the corrosion resistance of zinc electrodeposits

Abstract

The corrosion resistance of zinc electrodeposited on to an electropolished steel substrate at different current densities was investigated. Electrodeposition at 10 mA cm−2 resulted in fully epitaxial growth of zinc while completely non-epitaxial growth of zinc is obtained at 200 mA cm−2; at currents of 100 mA cm−2 both epitaxial and non-epitaxial components exist. The coatings deposited at 10 and 200 mA cm−2, which have only one texture component, reveal higher corrosion resistance. High percentage of (00·2) basal planes parallel to the substrate provides higher corrosion resistance for the coating at 200 mA cm−2. However, full epitaxial growth at 10 mA cm−2 provides fewer grain boundaries, which could be the reason for its higher corrosion resistance. The coating formed at 100 mA cm−2 allows easier hydrogen discharge and therefore shows lower corrosion resistance with respect to the others.