Non-dye Colors and Dye Colors for Oxidized Surface of Aluminum

Aluminum is widely used in construction and decoration due to its aesthetic appeal and corrosion resistance. The oxidized surface of aluminum can produce a range of colors, including non-dye colors (such as black and silver-white) and dye colors (such as gray, blue, red, and gold). However, there are some differences in terms of durability and color consistency among different colors.

Non-dye Colors: Black and Silver-white

The black oxide layer is created by dipping aluminum in a hot solution of sodium dichromate and sulfuric acid. This process produces a hard and scratch-resistant black layer that provides good wear resistance and good electrical conductivity. However, the black oxide layer is not as durable as other oxide colors and may fade or rust over time.

The silver-white oxide layer is created by anodizing aluminum with a neutral electrolyte solution. This process creates a uniform porous structure without damaging the surface layer of the aluminum. The result is a bright and silvery hue that is not only visually appealing but also provides excellent corrosion resistance. The silver-white oxide layer is the most durable and color-consistent among non-dye oxide colors.

Dye Colors: Gray, Blue, Red, and Gold

Gray oxide is created by placing aluminum in an environment containing various chemicals and carefully controlling the reaction conditions. The result is a rich and soft gray color that is well-adhered to the surface of the aluminum and has long-lasting durability. However, the gray color may fade or discolor over time due to sunlight exposure.

Blue, red, and gold oxide colors are created by dyeing the oxide layer with organic or inorganic dyes. The dye molecules penetrate the porous oxide layer and bond with the aluminum surface, producing a vibrant and durable color. However, dye colors may fade or change due to sunlight exposure, chemicals, or mechanical wear.

Conclusion

In summary, the oxidized surface of aluminum can produce a range of colors, including non-dye colors and dye colors. Among non-dye colors, the silver-white oxide layer is the most durable and color-consistent, while the black oxide layer is hard and scratch-resistant. Among dye colors, gray oxide provides a rich and soft gray hue that is well-adhered to the surface of the aluminum. Blue, red, and gold oxide colors provide vibrant and durable colors, but may fade or change over time due to sunlight exposure, chemicals, or mechanical wear. Understanding the differences between different oxide colors can help designers and manufacturers choose the best color for their specific applications.