Anodizing metal offers numerous advantages, both mechanical and aesthetic.

Mechanical Advantages

Anodizing can considerably increase the treated material’s corrosion resistance, protecting against both environmental and chemical corrosion caused by liquids, gases, and other materials. In this way, an anodized coating can extend the working life of a part up to ten times.

Anodizing, especially a variant produced under high current densities referred to as hard coat, improves metal’s wear resistance. It can be used to prevent galling of threaded components, and also improves surface lubricity. Anodized coatings can also be used in the creation of dielectric films for electrolytic capacitors. Aluminum, the most commonly anodized metal, is harder when anodized than untreated aluminum. Certain anodizing processes can also improve steam resistance.

Aesthetic Advantages

Thick, porous anodized coatings can easily by dyed in nearly any color, in finishes ranging from matte to high gloss. Similarly, high quality, full color images and other graphics can be printed into unsealed oxide layers using various printing processes. Thin, transparent anodized coatings can be used to add light interference effects. Anodizing a metal surface also provides better adhesion for paint primers and glues than untreated metal does. In general, anodic films are stronger and more adherent than most paints and metal platings, which makes them less prone to cracking and peeling from aging and wear.

Environmental Impact

Anodizing is far more environmentally friendly than most other metal finishing processes, such as chrome plating. The by-products of anodizing do not contain any heavy metals, VOCs (volatile organic compounds), or halogens. Common anodizing effluents, such as aluminum sulfate and aluminum hydroxide, can be recycled and reused in the manufacture of a wide range of products, from baking powder to newsprint to fertilizer. These effluents can also be used in industrial wastewater treatment.

Certain anodizing processes are also fully RoHS compliant.

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