Understanding the Properties and Applications of Aluminum
1. Basic Properties of Aluminum
Aluminum is a silvery-white metal known for its ability to form an oxide layer that protects it from corrosion in humid environments. It has a relative density of 2.7 g/cm³, a melting point of 660°C, and a boiling point of 2327°C. Aluminum is characterized by its high specific strength, excellent electrical and thermal conductivity, high reflectivity, and resistance to oxidation.
2. Types of Aluminum Products
● Profiles: Includes aluminum profiles, pipes, and rods.
● Plates: Consists of aluminum plates, foils, and strips (coils).
● Castings: Comprises aluminum castings and granules.
3. Common Aluminum Alloys and Their Applications
● 1100 Series: Offers excellent formability and corrosion resistance but is not suitable for high-strength applications. Common uses include storage containers, thin plate processing parts, heat exchangers, and reflective equipment.
● 2011 Series: Known for its machinability and high strength but limited corrosion resistance. It is ideal for precision parts such as volume shafts, optical components, and screws.
● 3003 Series: Provides higher strength compared to the 1000 series and is used for kitchen utensils, food processing equipment, and pressure vessels.
● 4A01 Series: Contains high silicon, making it heat and wear-resistant. Suitable for construction materials and mechanical parts.
● 5052 Series: A versatile alloy with medium strength, good corrosion resistance, and weldability. It is used in aircraft fuel tanks, oil pipes, and marine environments.
● 6061 Series: A heat-treated, corrosion-resistant alloy that offers high endurance but lower weld strength. It is commonly used in structural components for ships, vehicles, and land structures.
● 6N01 Series: A medium-strength alloy suitable for extrusion, used in large, thin profiles with complex shapes. It is ideal for vehicles and land structures.
● 6063 Series: A representative extrusion alloy with good extrudability and surface treatment properties. It is used in building guardrails, vehicles, and furniture.
● 7072 Series: Known for its low electrode potential, used primarily in anti-corrosion applications and heat exchangers.
● 7075 Series: One of the highest strength aluminum alloys with limited corrosion resistance. Often used in aerospace applications and thick plate forgings.
Material Selection Examples:
● For Hard, Coarse Surface Treatment: Choose 5000 series alloys such as 5052.
● For High Surface Treatment Requirements: Opt for 6000 series alloys such as 6063 or 6061.
● For Economical Options with Low Tensile Shape Requirements: Select 2000 series alloys like 2011.
● For High Strength and Load-Bearing Structures: Use 7000 series alloys such as 7075.
4. Surface Treatments for Aluminum Materials
● Anodizing after sandblasting or brushing.
● Electrophoresis Painting.
● Powder Coating and fluorocarbon coating after polishing.
● Mirror Polishing followed by electroplating.
● Wood Grain Heat Transfer Printing.
● Polymer PVC Coating.
5. Aluminum Profiles
Aluminum profiles are produced through the hot melting and extrusion of aluminum rods, resulting in various cross-sectional shapes. The main manufacturing processes include casting, extrusion, cutting, CNC machining, surface pretreatment, and coloring.
Surface treatments vary in cost, with titanium plating and electrophoresis being the most expensive, followed by wood grain thermal transfer, anodizing, and coating.
Applications of Aluminum Profiles:
● Architectural Profiles: Used in doors, windows, and curtain walls.
● Heat Sink Profiles.
● General Industrial Profiles: For machinery, equipment frameworks, and custom applications.
● Rail Vehicle Structures: In rail vehicle body manufacturing.
● Decorative Profiles: For frames and various decorative elements.
● Appearance Profiles: For home appliances, communication devices, and internal structures.
6. Aluminum Plates
● Thin Sheets: 0.15-2.0 mm.
● Conventional Boards: 2.0-6.0 mm.
● Standard Plates: 6.0-25.0 mm.
● Thick Plates: 25-200 mm.
● Extra Thick Plates: Over 200 mm.
Applications of Aluminum Plates:
● Polymer Thin Film Aluminum Plates: Used in electronic product casings and home appliances. They are noted for their ease of maintenance and color variety.
● Aluminum Plastic Composite Panels: Consist of a painted aluminum surface and a plastic core, suitable for building facades, ceilings, and transportation vehicles.
Aluminum Parts:
● Decorative Shells: Typically made of 0.4-0.8 mm thick aluminum, commonly using grades 6063/6061.
● Functional Shells: Usually 0.8-1.2 mm thick, using grades 5052/7075 for high strength and hardness.
For electronic product enclosures, it is essential to laser-engrave the oxide layer and ensure conductive grounding, as anodized aluminum oxide layers are non-conductive.