aluminumzinc

Aluminumzinc refers to a protective coating composed of aluminum and zinc that is applied to steel surfaces to improve corrosion resistance. The most common composition is roughly 55% aluminum and 45% zinc, with trace amounts of silicon in certain formulations. Variants used in different regions may have slightly different ratios and additional elements, leading to trade names such as Galvalume or Aluzinc.

The coating is typically applied by hot-dip coating steel in a bath of molten aluminum-zinc alloy, often followed by rolling and finishing processes. The resulting metallurgical bond provides a durable surface that combines the benefits of both metals. The aluminum-rich surface forms a stable, adherent oxide, while the zinc phase offers sacrificial protection, reducing the rate of rusting in many environments. This combination yields higher overall corrosion resistance than conventional zinc coatings in many coastal, industrial, and hot-humid settings, along with good formability and weldability.

Applications are widespread in building products and manufacturing. Aluminumzinc-coated steel is commonly used for roofing, siding, and exterior cladding, as well as for automotive panels, appliances, and agricultural equipment. The coatings can be supplied unpainted or with paint systems for color and additional protection. Trade names such as Galvalume and Aluzinc are associated with specific formulations and regional standards.

Limitations include higher cost relative to plain zinc coatings and potential differences in performance if the coating is damaged or if particular service conditions are encountered. Repairing or repainting damaged areas is often necessary to maintain corrosion resistance. Standards and specifications govern composition, coating thickness, and performance for different markets.