aluminized

Aluminized is an adjective describing a material that has been coated with aluminum, typically to improve corrosion resistance and high-temperature performance. In industrial contexts, it most often refers to steel or other metals coated with an aluminum-silicon alloy through a hot-dip process.

The coating is usually applied by passing the metal through a molten aluminum-silicon bath, then cooling. Common variants for steel are aluminized Type 1 (low silicon) and Type 2 (high silicon). The silicon content and coating thickness influence oxidation resistance and the behavior of the diffusion layer that forms at high temperatures.

Aluminized coatings provide enhanced resistance to oxidation and corrosion in oxidizing environments at elevated temperatures, often up to roughly 540–600°C depending on alloy composition and coating thickness. The coating also offers a reflective surface and can reduce emissivity. While cost-effective for many high-temperature applications, the coating can be damaged by deep bending, heavy abrasion, or mechanical wear, and damaged areas typically require re-coating or replacement.

Applications include automotive exhaust components, furnace and boiler parts, heat exchangers, and ductwork for hot gases. It is also used in other high-temperature equipment and in architectural or industrial components exposed to heat. Beyond metal coatings, the term aluminized can describe non-metal products that have an aluminum layer, such as aluminized paper or films, which combine a thin aluminum layer with paper or plastic to improve barrier properties and reflectivity for packaging or insulation.

In summary, aluminized materials carry an aluminum-based surface coating designed to extend life in corrosive and high-temperature environments, with particular prominence in steel-based components and select packaging applications.