Aluminum is a versatile metal used for the manufacturing of a wide range of parts and products. Similar to other metals, it sometimes requires additional protective layers to ensure it can resist damage from abrasives, chemicals, moisture, and other harsh environmental conditions within the intended application. While there are many treatments available that add protection to metals, one of the most commonly used for aluminum is anodizing.
Below, we provide an overview of anodized aluminum. We highlight what it is and how it is made, discuss key benefits of the material, and outline typical applications.
What Is Anodized Aluminum?
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Anodizing is an electrochemical treatment process that changes the surface chemistry of metal substrates. It increases the thickness of the natural oxide layer on the surface, which enhances the corrosion resistance, abrasion resistance, and aesthetic appearance of the material. The result of this process is finished aluminum that is durable and attractive. While this treatment method can be used for a variety of ferrous and non-ferrous metals, it is most commonly used for aluminum.
The anodizing process consists of the following steps:
- Placing the aluminum in a sulfuric acid bath with added electrolytes
- Attaching electrical charges to the metal and placing electrical charges in the bath
- Running electrical current through the circuit
- Sealing and coloring the newly formed protective layer
The negatively charged sulfuric acid bath pulls positive ions from the aluminum, while the positively charged aluminum attracts negative ions. As the dioxide molecules interact with the surface of the material, they form aluminum oxide. The sulfuric acid corrodes the metal to ensure the creation of a hard, thick, and porous oxidized layer that ranges from gray to black depending on the exact thickness. Placing the treated material in warm water hydrates the ions, which shrinks the pores and seals the surface layer. The addition of dyes in the sealing water enables manufacturers to color the layer.
Advantages of Anodized Aluminum
Anodized aluminum offers many advantages over other standard materials, such as:
- Higher durability. Anodized aluminum has enhanced abrasion, corrosion, and impact resistance. Additionally, since the finish is made from the aluminum, rather than applied on the surface, it is unlikely to chip, flake, or peel. As a result, it is long-lasting, making it a cost-effective, long term finishing option.
- Lower material weight. Anodizing provides a good strength-to-weight ratio. This maintains the aluminum’s inherent qualities with added durability.
- Greater recyclability. The anodization process does not affect the highly recyclable quality of aluminum.
- Better aesthetic quality. Anodization enables manufacturers to minimize or eliminate surface variations without losing the metallic appearance of the material. Since there are many color and finish options for anodized surfaces, you can customize aluminum components to their exact aesthetic requirements – just what we specialize in!
Applications of Anodized Aluminum
Due to its numerous advantageous functional and aesthetic qualities, anodized aluminum finds application in a wide range of industries. Examples of typical uses include:
- In the aerospace, automotive, marine, and transportation industries: lightweight components for aircraft, boats, cars, and trains
- In the architectural industry: structural elements (e.g., roofs, frames, and supports), visual elements (e.g., lighting fixtures, railings, and trellises)
- In the art industry: painting surfaces, sculptures
- In the consumer goods industry: small appliances, luxury vehicles, sporting goods
- In the food and beverage industry: kitchen equipment, cooking instruments, display cases
- In the furniture industry: beds, storage chests, tables
Contact Tri-State Aluminum for Your Anodized Aluminum Needs
Want to learn more about anodized aluminum? Ask the experts at Tri-State Aluminum!
At Tri-State Aluminum, we supply anodized bars, rods, tubes, and custom stock shapes for building and manufacturing projects. Our two-step electrolytic coloring process allows us to meet any custom color need ensuring your components meet your aesthetic specifications. If you would like to learn more about our capabilities and how we can benefit your next project, contact us or request a quote today.