Black aluminium sheet is a specially treated aluminum alloy sheet that appears black on the surface, typically through processes such as anodizing or spray coating. It possesses a variety of excellent properties and is widely used in various fields. Black aluminum sheet has a wide range of applications, including but not limited to building facades, interior decoration, vehicles, and electronic product casings.
1. Base Material and Specifications
- Base Material:
Common aluminum alloy series include the 1000 series (such as 1050 and 1060), 3000 series (such as 3003), 5000 series (such as 5005 and 5052), and 6000 series (such as 6061 and 6063) aluminum alloys. Different series of aluminum alloys have different performance characteristics. For example, the 1000 series offers excellent ductility and corrosion resistance, the 3000 series aluminum offers excellent formability and weldability, the 5000 series aluminum offers high corrosion resistance and strength, and the 6000 series offers excellent mechanical properties and corrosion resistance.
- Specifications:
Thickness typically ranges from 0.2mm to 12mm, widths typically range from 80mm to 2650mm, and lengths can be customized upon request.
2. Surface Treatment Methods
Color coating and anodizing are two core surface treatment processes for black aluminium sheets. Their key differences lie in their processing principles, performance and applicable scenarios. A detailed comparison is provided below:
- Process Principle
Color Coating (Powder/Liquid Spraying): Black paint (powder/liquid) is sprayed onto the aluminum sheet surface, which then cures to form a protective film.
Anodizing: Electrolysis forms a porous black oxide film (Al₂O₃) on the aluminum sheet surface, sealing the pores and enhancing performance.
- Appearance and Texture
Color Coating: Black coated aluminum sheet are available in matte, semi-matte and gloss finishes, with high color uniformity and the ability to achieve a variety of textures (such as frosted and wood grain).
Anodizing: Mostly matte or semi-matte finishes, with a natural metallic black color, a more delicate texture, and a metallic luster.
- Weather Resistance
Color Coating: Relatively good (high-quality powder spray coating can withstand 5-10 days of outdoor use). Years), but prolonged exposure to sunlight may cause fading and coating degradation.
Anodizing: Superior, with a strong bond between the oxide film and the substrate, offering outdoor weather resistance of over 10 years and resisting fading.
- Abrasion Resistance
Color Coating: Medium, with a low coating hardness (typically HV 200-300), which can be easily scratched by sharp objects, exposing the base.
Anodizing: Anodized aluminum sheet is higher, with a high oxide film hardness (typically HV 300-500), offering strong scratch resistance and resistance to wear.
- Corrosion Resistance
Color Coating: Depends on the integrity of the coating; damaged coatings can easily cause rust (repair requires touch-up).
Anodizing: Stronger, with the oxide film inherently resistant to acids and alkalis. Sealing pores isolates moisture, limiting oxidation to localized areas and preventing widespread damage.
- Processability
Color Coating: The coating has limited ductility, making bending and deep drawing prone to cracking and peeling.
Anodizing: The oxide film offers good toughness, adapts to light bending and stamping, and is less prone to cracking.
- Cost
Color coating: A lower cost (especially powder spraying), making it suitable for high-volume, large-area applications.
Anodizing: A higher cost (complex electrolytic process), suitable for applications with high performance requirements.
Features of Black Aluminium Sheet:
- High Corrosion Resistance:
After anodizing and other treatments, the oxide film formed on the aluminum sheet effectively prevents oxidation and corrosion, extending its service life and maintaining a stable appearance in various climates.
- Good Mechanical Properties:
Depending on the alloy selected, black aluminum sheet exhibits high strength and toughness, capable of withstanding certain external forces. It also has excellent processability, making it easy to cut, form, and weld, meeting various complex design requirements.
- Aesthetic Appearance:
Black offers a stylish, modern appearance with a unique visual effect. Various surface treatments can achieve varying finishes, from glossy to matte, making it suitable for a variety of decorative applications.
- Lightweight:
Due to its low density, black aluminum sheet is lightweight, making it easy to handle and install, making it an advantage in weight-sensitive applications such as aviation and automotive.
Applications of Black Aluminum Sheet:
- Architectural Decoration:
Used for the decoration of building exteriors, curtain walls, doors, windows, balconies, and other areas, adding a modern aesthetic while ensuring long-term durability.
- Household Goods:
Suitable for furniture, kitchenware, and home decorations, such as furniture frames and handles, and kitchen cabinet panels, creating both aesthetics and practicality.
- Electronic Products:
Commonly used in the casings of electronic products such as mobile phones, tablets, and computers, its aesthetics, lightweight design, excellent heat dissipation, and corrosion resistance enhance the product's quality and appearance.
- Transportation:
Used in the exterior decoration and component manufacturing of vehicles such as automobiles and motorcycles, such as automotive body moldings, wheel hubcaps, and motorcycle fuel tank caps, enhancing the vehicle's personalization and aesthetics.
- Advertising Signs:
Due to its excellent weather resistance and eye-catching appearance, it is often used in billboards and signage, maintaining clear visibility in outdoor environments for extended periods.