Surface Finishing What is anodizing?

Posted by FORMEX Nancy
3
Tech Innovation
1 hour ago
7 Views

Anodizing is an electrolytic process that creates a durable, corrosion-resistant oxide layer on the surface of aluminum (and other non-ferrous metals like titanium). This layer is integral to the metal—unlike paint or plating, it won’t peel or chip—and can be dyed in vibrant colors for aesthetic or functional purposes.

How It Works

The process immerses the metal part in an electrolytic bath (typically sulfuric acid) and passes an electric current through it: the part acts as the anode, causing oxygen ions to react with the metal surface and form a porous aluminum oxide (Al₂O₃) layer. The pores are then sealed (via hot water or chemical treatment) to lock in color and boost corrosion resistance, or left open for specialized coatings (e.g., lubricant retention).
  • Corrosion resistance: The oxide layer shields aluminum from moisture and chemicals, ideal for outdoor or marine applications.
  • Wear resistance: Harder than bare aluminum, it withstands scratches and abrasion (hard anodizing can reach 60+ HRC).
  • Aesthetic flexibility: The porous layer absorbs dyes, enabling custom colors (black, red, gold) while maintaining a metallic finish.
  • Adhesion: Improves bonding for paints or adhesives, enhancing durability of secondary coatings.

Common Uses

Anodizing is widely used in aerospace components, automotive parts, consumer electronics (e.g., phone casings), architectural trim, and industrial machinery—anywhere aluminum needs enhanced performance or visual appeal.
It’s a cost-effective, eco-friendly process that extends the lifespan of aluminum parts while adding customizable value.

  • Some common anodizing Color

    Anodizing alone cannot conceal tool marks, so for cosmetic parts during processing, we typically need to confirm whether sandblasting should be carried out in conjunction with anodizing.

    This is especially true for natural anodizing—differentiation can only be made by subtle details, as the finish typically has a distinct luster compared to the base metal’s natural appearance after anodizing.



    Application of Anodizing+ Sandblasting +Masking

    1. CNC Texturing: First, fine knife patterns are carved into the metal surface using CNC machining.

    2. Sandblasting: The surface is treated with high-pressure sandblasting to cover certain areas of the knife patterns, giving it a uniform matte finish.

    3. Anodizing: Anodizing treatment is applied to enhance corrosion resistance while adding color.

    This method combines the precision of machining with the matte texture of sandblasting, and the anodizing enhances durability and uniformity of appearance.

    Comments
    avatar
    Please sign in to add comment.
    Advertise on APSense
    This advertising space is available.
    Post Your Ad Here
    More Articles