Anodising is an electrochemical process used to create a durable, corrosion-resistant oxide layer on the surface of metal components, typically aluminum and its alloys. This process is commonly used to improve the durability, aesthetics, and performance of precision components, especially in industries like aerospace, automotive, electronics, and manufacturing.

Key Points of Anodising:

1. Enhanced Durability: Anodising increases the hardness of the metal surface, making it more resistant to scratching, wear, and abrasion. The anodic layer also protects the base metal from corrosion by acting as a barrier.

2. Corrosion Resistance: The oxide layer that forms during anodizing is highly resistant to corrosion and can protect the component from environmental factors like moisture, salt, and chemicals.

3. Surface Finishing: Anodising provides a uniform and consistent finish that can be tailored for aesthetic purposes. The surface can have a matte or shiny finish, and various colors can be added using dyes or pigments.

4. Electrical Insulation: The anodised layer on aluminum is an electrical insulator, making it useful in applications where electrical insulation is required.

5. Dimensional Precision: The anodising process can affect the dimensions of the component slightly, as the oxide layer builds up on the surface. However, with careful control of the process, the dimensional changes can be minimized, which is crucial for precision components.

The Process of Anodising:

1. Cleaning: The component is thoroughly cleaned to remove oils, dirt, and other contaminants that could affect the anodising process.

2. Electrochemical Treatment: The component is immersed in an electrolyte solution (sulfuric acid) and subjected to an electrical current. This causes the aluminum's surface to oxidize and form a thickened, protective oxide layer.

3. Sealing: After anodising, the oxide layer is sealed by immersing the component in hot water or a chemical sealant, which closes the pores of the anodised layer, making it more resistant to corrosion and wear.

Types of Anodising We Provide:

• Semi-hard Anodising: The most common form, providing good corrosion resistance and a good surface finish.

• Hard Anodising: Used for heavy-duty applications, where a thicker, more durable oxide layer is needed.

• Color Anodising: Process where the anodized aluminum surface is dyed to produce a wide range of colors while maintaining the durability and protective benefits of anodizing. The color results from either adding a dye to the anodizing bath or using an electrolytic process to create natural colors. This process is commonly used in industries where both the aesthetic appearance and the functional performance of the material are essential.

How Color Anodising Works:

1. Electrochemical Process: During the anodising process, aluminum is immersed in an electrolyte solution (sulfuric acid), and an electrical current is passed through the bath. This creates an oxide layer on the surface of the aluminum. The oxide pores formed during this process can absorb dyes, allowing for coloring.

2. Dyeing: After anodising, the aluminum is immersed in a dye bath where it can absorb various colors. The dye is absorbed into the porous surface and remains there as the pores are sealed during the final sealing stage. The color is stable and long-lasting because it is embedded within the oxide layer, not just on the surface.

3. Electrolytic Coloration: Some anodising processes, such as hard anodising, can produce natural colors without dyes, primarily due to the thickness of the oxide layer. The color variations are a result of light interference and the thickness of the oxide film. Natural colors include shades of gold, bronze, brown, and gray, which are created during the anodising process.

Our Color Range:

• Clear (Transparent): A natural anodized finish that preserves the metallic appearance of the aluminum, with enhanced protection and durability.

• Black: One of the most common colors, providing a sleek, professional finish while also offering enhanced UV protection.

• Gold: Achieved using dyes.

• Yellow: Achieved using dyes.

• Green: Achieved using dyes

• Blue: Achieved using dyes.

• Red: Achieved using dyes.

Aluminum Alloys and Anodising

Aluminum alloys are widely used in various industries due to their excellent strength-to-weight ratio, corrosion resistance, and versatility. When it comes to anodising, the choice of aluminum alloy can significantly affect the outcome in terms of finish, performance, and durability. Different alloys have distinct properties that impact how they react during the anodising process.

The selection of the aluminum alloy for anodising is crucial for achieving the desired properties in terms of appearance, strength, and resistance to corrosion. Each alloy behaves differently during anodizing, and knowing the alloy's characteristics can help optimize the process to meet specific requirements.

Impact of Alloy Composition on Anodising:

1. Oxide Layer Formation: The primary purpose of anodising is to form a protective oxide layer on aluminum. The alloy's composition influences how easily this layer forms. Alloys with higher silicon or copper content may have challenges forming a consistent oxide layer, which can affect the final finish's appearance and durability.

2. Color Consistency: The composition also affects the ability to dye the anodized layer. Alloys with higher copper or magnesium can interfere with dye absorption, leading to inconsistent or uneven color.

Best Aluminum Alloy Used for Anodising:

1. Series 6000 (Aluminum-Magnesium-Silicon Alloys)

   • Composition: Aluminum with magnesium and silicon (e.g., 6061, 6082).

   • Anodising: 6000-series alloys are among the most commonly anodised. They offer a good balance of strength, corrosion resistance, and excellent anodising response. They form strong, durable oxide layers that are easy to color.

   • Applications: Structural components, aerospace parts, architectural elements, and consumer goods like sporting equipment.