AA 2639 is an aluminum alloy known for its high strength and excellent machinability. It is commonly used in aerospace and structural applications where durability and performance are critical.
Composition and Properties
AA 2639 is a copper-based alloy, part of the 2xxx series of aluminum alloys. These alloys are characterized by high strength and excellent fatigue resistance. The typical composition includes:
- Aluminum (Al): Balance
- Copper (Cu): 3.9–5.0%
- Silicon (Si): 0.50–0.90%
- Iron (Fe): 0.50% max
- Magnesium (Mg): 0.2–0.8%
- Manganese (Mn): 0.4–1.2%
- Zinc (Zn): 0.25% max
- Titanium (Ti): 0.15% max
These elements contribute to the alloy’s high strength and good machinability.
Mechanical Properties
AA 2639 exhibits the following mechanical properties:
- Tensile Strength: Up to 480 MPa
- Yield Strength: Up to 435 MPa
- Elongation: Approximately 7–11%
These properties make AA 2639 suitable for applications requiring high strength and durability.
Applications
Due to its favorable properties, AA 2639 is used in various industries, including:
- Aerospace: Structural components, aircraft fittings
- Military: Vehicle armor, weapon components
- Automotive: High-performance parts
- Construction: Structural frameworks
Its high strength-to-weight ratio makes it ideal for applications where weight savings are essential.
Fabrication and Heat Treatment
AA 2639 can be fabricated using standard machining processes. It responds well to heat treatment, which can enhance its mechanical properties. Common tempers include T4 and T6, which involve solution heat treatment and artificial aging.
FAQs
1. What is AA 2639 aluminum alloy?
AA 2639 is a high-strength, copper-based aluminum alloy known for its excellent machinability and fatigue resistance.
2. What are the common applications of AA 2639?
It is commonly used in aerospace, military, automotive, and construction industries for structural components requiring high strength.
3. Can AA 2639 be welded?
Welding AA 2639 can be challenging due to its copper content, which may lead to hot cracking. Specialized welding techniques and filler materials are required.
4. How does heat treatment affect AA 2639?
Heat treatment can significantly enhance the mechanical properties of AA 2639, improving its strength and hardness.
5. Is AA 2639 corrosion-resistant?
While AA 2639 has moderate corrosion resistance, it is often coated or anodized for applications where enhanced corrosion resistance is needed.
AA 2639 aluminum alloy offers a combination of high strength and good machinability, making it suitable for demanding applications across various industries. Understanding its properties and appropriate fabrication methods ensures optimal performance in its intended applications.
