The pure zinc layer is the very top of the hot-dip galvanized coating, consisting almost entirely of zinc.
This pure zinc layer has a dense and complex hexagonal crystal structure. It is characterized by being soft, tough, and highly ductile, which makes the structure resistant to damage during mechanical processing.
In addition to the pure zinc layer (also known as the η layer), hot-dip galvanizing is composed of two other "alloy layers": the δ1 layer, which has a dense structure with toughness and ductility, and the zeta ζ layer, which has a columnar structure and is relatively hard and wear-resistant.
Altogether, the coating consists of these three layers. Regarding anti-corrosion performance to prevent red rust, the thickness of the pure zinc layer, which is primarily composed of zinc, has the most significant impact.