Aluminum Alloy Surface Treatment: What You Need to Know

In the mid-19th century, due to the very backward technology of aluminum smelting in France, the ministers of the princes could only use silver tableware at banquets, and only Napoleon II used an aluminum bowl.

With the application of electrolytic aluminum technology, aluminum has become increasingly integrated into public life. The development of aluminum alloy surface treatment technology has made aluminum not only have high practical value but also aesthetic value.

Here are six common aluminum alloy surface treatment processes. What else do you know?

Aluminum Alloy Surface Treatment

Metal materials are being used more and more in existing products because they can better reflect product quality and highlight brand value. Among many metal materials, aluminum is the first choice of various manufacturers because of its easy processing, good visual effect, and rich surface treatment methods.

The surface treatment of aluminum profiles is mainly divided into:

  • Sandblasting (forming a matte pearl silver)
  • Polishing (forming a mirror)
  • Drawing (forms a satin-like effect)
  • Plating (covering a layer of other metals)
  • Spraying (covering other non-metallic coatings)

Let’s take a look at the surface finishing process of aluminum and aluminum alloys in our daily products.



The process involves cleaning and roughening the metal surface using high-velocity sand flow.

This method of aluminum surface treatment can achieve a certain degree of cleanliness and different levels of roughness on the surface of the workpiece, which improves the mechanical properties of the workpiece’s surface.

As a result, the workpiece’s fatigue resistance is improved, the coating’s adhesion is increased, the durability of the coating film is prolonged, and the coating’s leveling and decoration are also facilitated.

This process is often seen in various Apple products and is increasingly used in the manufacturing of TV sets or middle frames.



Mechanical, chemical, or electrochemical methods are used to reduce the surface roughness of the workpiece to obtain a bright, flat surface.

The polishing process is mainly divided into mechanical polishing, chemical polishing, and electrolytic polishing.

Aluminum parts can be mechanically polished and electrolytically polished to achieve a mirror effect close to that of stainless steel, giving people a feeling of high-grade simplicity and fashionable future. Of course, this surface finish is prone to fingerprints and requires more care.


Metal wire drawing

Metal wire drawing is a manufacturing process in which sandpaper is used to repeatedly scrape the surface of the material to produce a series of fine lines.

Drawing can be divided into straight drawing, random drawing, swirl drawing, and thread drawing.

The metal wire drawing process can create fine lines on the surface of the material, producing a silky and matte finish. The resulting product combines both style and technology.



The diamond carving knife is mounted on the spindle of a high-speed engraving machine (typically 20,000 rpm) to carve parts, generating a highlighted area on the surface of the product.

The brightness of the highlighted area is affected by the speed of the milling bit. The faster the speed, the brighter the light, while the slower the speed, the darker the light and it is easy to produce knife marks.

High-gloss high-light cutting is especially used in mobile phones, such as the iPhone 5. In recent years, some high-end TV metal frames have adopted high-gloss milling technology, combined with anodizing and wire drawing technology, making the TV appear fashionable and technologically advanced.



Anodization refers to the electrochemical oxidation of a metal or alloy. It is the process of forming an oxide film on the surface of an aluminum article (anode) and its alloy under corresponding electrolyte and specific process conditions due to the application of current.

Anodizing can not only solve the defects of aluminum surface hardness and wear resistance, but also prolong the service life of aluminum and enhance its appearance. It has become an indispensable part of aluminum surface treatment and is the most widely used and highly successful process.

Two-color anodizing

Two-color anodizing

Two-color anodization refers to the process of anodizing a product and imparting a different color to a particular area.

The two-color anodizing process is complicated and costly; however, the contrast between the two colors can better reflect the high-end and unique appearance of the product.

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