Study on the Spangle in the Hot-Dip Galvanized Coating

Abstract

The investigation dealt with the influence of aluminium, and tin additions on the spangles (flowers of zinc) on galvanized coating which are of commercial importance because of theirpleasing and aesthetic appearance. The spangles of the galvanized coating produced byusing the elecrolytic-grade zinc baths and the electrolytic zinc baths contained with 0.5w/oor lower aluminium content were formed the grain-shaped spangles with a weak contrast.On the other hand, the spangles of galvanized coating, by using an electrolytic zinc bath withabout 0.1w/o or higher tin concentration, resulted in the larger and regular spangles with afeathering aesthetic appearance.
It was possible to find a satisfactory explanation for such influence of nucleation of spanglesas function of coating time gives a similar shape to the formal frequency of nucleous formationas a function of supercooling. The macro- and microscopic growth of spangles werefound to have the linear rate.