Aluminum Anodizing Surface Treatment

We offer aluminum anodizing services, providing surface treatments tailored to your specifications.

Aluminum Anodizing Specifications

Type I anodizing and II anodizing processes can produce a thin oxide layer on aluminum parts with moderate corrosion resistance. Therefore, anodizing process is very suitable for parts that require aesthetics and moderate protection.

Finish Type	Color	Glossiness	Thickness (μm)	Visual Appearance
Clear Glossy	Clear	Glossy	8–12	Enhances the metal's natural luster with a shiny surface.
Clear Matte	Clear	Matte	8–12	Provides a soft, non-reflective finish with a uniform look.
Black Glossy	Black	Glossy	8–12	Deep black color with a reflective, decorative finish.
Black Matte	Black	Matte	8–12	Low-gloss black surface ideal for technical, low-glare use.
Color Glossy	Red / Blue / Gold	Glossy	10–20	Bright, colored glossy finish with strong visual impact.
Color Matte	Red / Blue / Gold	Matte	10–20	Soft, colored matte finish with reduced reflectivity.

Advantages

Enhanced corrosion resistance due to the formation of an unreactive oxide coating
Improvement in aesthetic appeal as it offers a beautiful finish with different anodizing colors
Insulative properties for parts that need dampening of electrical conductivity
Anodized parts are easier to clean

Notes

Use sandblasting (#120) as a pre-treatment, or the machining marks on the surface cannot be completely covered
Different materials, thicknesses, and lots will have a certain degree of color difference
Non-standard and custom colors are available upon request

Standard Anodizing Color Options

Yajia Aluminum offers a wide range of color options for your project. For specific RAL or Pantone colors, please use the form or email [email protected]. Anodized products may have color differences due to factors such as oxide layer thickness, oxide layer structure, alloy composition, pretreatment method, coloring process and sealing treatment. If you have any questions, please contact us.

Aluminum Anodizing quality inspection

All anodized aluminum components are subjected to comprehensive quality inspections to ensure consistency in appearance, coating integrity, and corrosion resistance. Our inspection protocols follow international standards such as ISO 7599 and ISO 3210, and are designed to meet the requirements of both industrial and architectural applications.

Inspection Criteria Include:

Film Thickness Measurement: Oxide layer thickness is measured using eddy current or coulometric methods, typically ranging from 8–25 μm for standard anodizing and ≥25 μm for hard anodizing.

Surface Appearance Check: Visual inspection under controlled lighting conditions is used to assess color uniformity, gloss level, and surface finish (matte, satin, or glossy).

Color Consistency: Color meters or spectrophotometers are used to evaluate any variation across batches, particularly for dyed or colored anodizing.

Adhesion & Scratch Resistance: Surfaces are tested for hardness and resistance to mechanical abrasion, especially for hard anodized coatings.

Sealing Test: The quality of sealing (hot water or nickel acetate) is verified by spot testing methods (e.g., dye spot test or acid dissolution) to ensure corrosion resistance.

Corrosion Resistance Test: Accelerated neutral salt spray testing (ISO 9227) may be conducted on request for marine or exterior-grade applications.

Dimensional and Edge Integrity:Profiles are checked for deformation or tolerance deviation due to the anodizing process.

All test data are recorded for quality traceability. Upon request, we can provide test reports or third-party certification to support your quality assurance needs.

Our Anodized Aluminum Case Studies

Anodizing Extrusion Profile

Anodizing CNC Part

Anodizing Assembly Product

Anodizing Aluminum Enclosure

Perfect Your Project's Finish

Your designs deserve the best. Enhance durability and appeal with our various finishing options. Part surfacing finishing techniques can either be for functional or aesthetic purposes. Each technique has requirements, such as materials, color, texture, and price. Step up the quality of your projects today!

About Aluminum Anodizing

What Is Aluminum Anodizing?

Aluminum anodizing is an electrochemical process that converts the metal surface into a durable, corrosion-resistant, anodic oxide layer. This oxide layer is fully integrated with the underlying aluminum substrate and provides improved surface hardness, wear resistance, and enhanced appearance. Anodizing is widely used in architectural, automotive, aerospace, and consumer product applications.

How Does the Anodizing Process Work?

The anodizing process involves immersing aluminum parts into an acid electrolyte bath and passing an electric current through the solution. The aluminum serves as the anode, and oxygen ions from the electrolyte combine with aluminum atoms to form aluminum oxide. The process can be controlled to achieve varying thicknesses and porosities, depending on performance or decorative requirements.

Types of Aluminum Anodizing

There are three main types of anodizing:

Type I (Chromic Acid Anodizing): Thin coating, used for corrosion resistance.
Type II (Sulfuric Acid Anodizing): Most common, allows coloring and moderate thickness.
Type III (Hardcoat Anodizing): Thick, dense coatings ideal for high-wear applications.

Each type is selected based on the specific application’s mechanical, environmental, or aesthetic demands.

Benefits of Anodizing Aluminum

Anodizing enhances aluminum with improved corrosion resistance, surface hardness, UV stability, and wear resistance. It also provides a porous surface ideal for dye absorption, enabling long-lasting color finishes. Unlike paint or plating, anodized layers do not peel or chip and require minimal maintenance.

Anodizing vs. Other Surface Treatments

Compared to powder coating or painting, anodizing forms a part of the aluminum surface rather than a layer on top. This integration offers superior adhesion and durability. While anodizing enhances natural metallic appearance, other treatments may offer more color range but lower wear resistance or longevity under UV exposure.

Coloring Options in Anodizing

During the anodizing process, the oxide layer’s porosity allows it to be dyed in a range of colors such as black, bronze, gold, blue, or red. Electrolytic and organic dye methods are commonly used. Colorfastness depends on sealing quality and intended environmental exposure.

Common Applications of Anodized Aluminum

Anodized aluminum is widely used in curtain walls, window frames, electronic enclosures, cookware, signage, and transportation components. Its combination of aesthetic flexibility, durability, and low maintenance makes it suitable for both industrial and consumer-facing applications.

Limitations of Anodizing

While anodizing offers many benefits, it is limited to aluminum and a few other non-ferrous metals. It does not improve structural strength and may be unsuitable for components exposed to highly alkaline environments. Inconsistent alloy compositions can also affect anodizing uniformity.

Anodizing Compatibility with Aluminum Alloys

Not all aluminum alloys anodize equally. Alloys in the 6xxx series (e.g., 6061, 6063) respond well, producing consistent finishes. In contrast, high-copper or high-silicon content alloys may yield dark, blotchy, or uneven coatings. Proper alloy selection is essential for visual and functional results.

Maintaining and Cleaning Anodized Surfaces

Anodized surfaces are easy to maintain with routine cleaning using mild soap and water. Abrasive cleaners or acidic/alkaline solutions should be avoided to preserve the integrity of the oxide layer. Periodic maintenance helps retain appearance and prolong service life, especially in outdoor environments.