Color Anodized Aluminum Sheet

2023-07-26

After undergoing oxidation treatment, color anodized aluminum sheet will present different colors, mainly including transparent, black, brown, gold, bronze or red. The formation of different colors is related to the purity of the oxide layer, reaction environment, reaction time, and thickness of the oxide layer. Despite the different colors, the high strength, durability, and environmental friendliness of aluminum sheets remain unchanged. When using anodized aluminum sheets, it is necessary to select sheets of different colors and thicknesses according to actual needs, and pay attention to storage, processing and usage.

1. Classification of color anodized aluminum sheet

After undergoing oxidation treatment, aluminum forms a layer of oxide with different thicknesses, resulting in different colors of aluminum plates. Generally, the anodized aluminum sheet can be divided into the following four colors:

1. Transparent oxide layer: The thickness of the oxide layer is between 0.5-10 micrometers, appearing silver or light blue in sunlight.

2. Black oxide layer: The thickness of the oxide layer is between 5-20 micrometers, appearing black or dark gray in sunlight.

3. Brown oxide layer: The thickness of the oxide layer is between 20-60 micrometers, appearing brown in sunlight.

4. Golden or red oxide layer: The thickness of the oxide layer is between 60-150 micrometers, appearing golden or red in sunlight.

Second, the formation principle of color anodized aluminum sheet

The oxidation on the surface of the anodized aluminum sheet is formed by the reaction between aluminum and oxygen molecules. The thickness and color of the oxide layer are different due to different reaction conditions and reaction times. Specifically, the formation of oxide color is mainly due to the following factors:

1. Different purities: Aluminum products with high purity will form a transparent oxide layer after oxidation, while impure aluminum will produce different colors.

2. Different reaction environments: Environmental factors such as temperature, humidity, composition of the oxidizing solution, and immersion time will also affect the color of the oxide layer.

3. Different thickness of the oxide layer: The different thickness of the oxide layer will give the anodized aluminum sheet different colors. In general, a transparent oxide layer with a thickness of less than 0.5 micrometers will appear silver-white or light blue, while a high-thickness oxide layer will appear black, brown, gold, or red.

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