zincaluminummagnesium

Zincaluminummagnesium, often abbreviated as ZAM, is a metallic coating primarily used for corrosion protection on steel. It is an alloy consisting of approximately 55% aluminum, 43.4% zinc, and 1.6% magnesium. This specific composition provides a synergistic effect, offering enhanced corrosion resistance compared to traditional galvanized (zinc-coated) or aluzinc (aluminum-zinc alloy without magnesium) coatings.

The magnesium in the ZAM coating plays a crucial role in its performance. It contributes to the formation of a more stable and protective passive layer on the surface of the metal. This layer, a combination of zinc and aluminum oxides and hydroxides, acts as a barrier against corrosive elements like moisture and salt. Furthermore, the presence of magnesium also improves the coating's adhesion to the steel substrate.

ZAM coatings are typically applied to steel through a continuous hot-dip process. The steel strip is cleaned, annealed, and then passed through a molten bath of the ZAM alloy. As the strip emerges from the bath, excess coating is wiped off to achieve a uniform thickness. This coating is known for its excellent formability, weldability, and paintability, making it suitable for a wide range of applications. These include roofing, wall cladding, automotive components, and appliances, where long-term durability and aesthetic appeal are important.