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Aluminum Anodizing

Aluminum is well-suited to anodizing, making it one of the most respected and commonly used materials for consumer, commercial and industrial products in comparison to other metals. Other nonferrous metals, such as magnesium and titanium, can be anodized, but the composition of aluminum makes it ideally suited to the process.

End shot of multiple extruded aluminum shapes

Anodizing is an electrochemical process which converts the surface of the metal into a long-lasting, high performance aluminum oxide finish. Because it is integrated into the metal rather than just applied to the surface, it cannot peel or chip.

This protective finish makes it very hard and durable, and enhances its resistance to corrosion. Depending on the process, the anodized finish is the second hardest substance known to man, exceeded only by the diamond.

The anodizing process is, in simplified terms, the highly controlled enhancement of a phenomenon that already occurs naturally - oxidation. The aluminum is immersed in an acid electrolyte solution through which attached electrodes pass an electric current at very low temperatures. The result is a high performance, hardcoat surface. However, the metal remains porous so it can be colored and sealed, or undergo additional processing, if desired.

Benefits of Anodizing Aluminum

Aluminum anodizing creates an extremely hard surface that can withstand extreme wear and tear. This includes industries such as military and defense, construction, applications such as elevator doors and escalators, and even home cookware. Anodized aluminum has been used in the infrastructure of buildings, such as the Sears Tower in Chicago, Illinois.

The primary benefits of anodizing aluminum include:

  • Durability
    The finished product will enjoy a long lifespan and require little maintenance.
  • Stable color
    Anodizing dyes seep into the metal making them very stable. Anodized aluminum maintains its color in spite of exposure to UV rays. It will not flake, peel or chip, and extrusions will look factory new for years.
  • Low maintenance
    Evidence of wear or abrasions from the extrusion process, installation, or from frequent handling and excessive cleaning are rare. Anodized aluminum is easily restored to its original luster with gentle cleaning.
  • Beauty
    Anodized aluminum maintains its metallic appearance but can easily accommodate color and gloss applications.
  • Value 
    Finishing costs and maintenance costs are low, giving anodized products a better value in the long term.

Hydro Extrusion offers a full range of services in clear and electrolytic colored anodic coatings as well as acid etch, as well as an exceptional selection of extruded aluminum shapes, sizes, alloys and tempers, utilizing both direct and indirect extrusion methods.

Complete solutions are available for extruded aluminum products required by the automotive, mass transit, bridge decking, and solar/renewable energy industries, as well as green applications for the building & construction market. Some aluminum alloys cannot be anodized, so be certain to discuss your project with us beforehand so we can suggest suitable alloys.