2024A Aluminum alloy,Aluminum 2024A alloy,E FORU

### **2024A Aluminum Alloy Product Introduction** **Overview** 2024A Aluminum Alloy is an advanced, high-strength aluminum-copper-magnesium alloy, representing an evolution of the classic 2024 alloy. The "A" suffix typically denotes a modified composition with tighter control over impurities and the addition of small amounts of zirconium, resulting in improved toughness, better damage tolerance, and enhanced consistency. It is one of the most widely used alloys in the aerospace industry for its exceptional strength-to-weight ratio and fatigue performance, typically supplied in the T3 or T4 temper (solution heat-treated and naturally aged) for sheet and plate forms. --- #### **1. Chemical Composition (Typical Weight %)** The composition of 2024A is carefully balanced to optimize strength and damage tolerance, with stricter controls than standard 2024. | Element | Minimum (%) | Maximum (%) | Notes | | :--- | :--- | :--- | :--- | | **Aluminum (Al)** | Balance | Balance | - | | **Copper (Cu)** | 3.8 | 4.5 | Primary strengthening element, forms S-phase (Al₂CuMg) precipitates. | | **Magnesium (Mg)** | 1.2 | 1.8 | Works with Cu to form the primary strengthening S-phase precipitates. | | **Manganese (Mn)** | 0.30 | 0.9 | Forms dispersoids (Al₂₀Cu₂Mn₃) that control grain structure and improve toughness. | | **Iron (Fe)** | - | 0.20 | Tighter control than standard 2024 to improve ductility and fracture toughness. | | **Silicon (Si)** | - | 0.15 | Tighter control than standard 2024 to improve ductility and fracture toughness. | | **Zirconium (Zr)** | 0.05 | 0.15 | **Key modification.** Forms fine Al₃Zr dispersoids that inhibit recrystallization, leading to a finer grain structure for improved toughness. | | **Zinc (Zn)** | - | 0.25 | Impurity. | | **Titanium (Ti)** | - | 0.10 | Grain refiner. | | **Others (Each)** | - | 0.05 | - | | **Others (Total)** | - | 0.15 | - | **Key Point:** The tighter control on impurities (Fe, Si) and the addition of **Zirconium (Zr)** are the key differentiators for 2024A. This refined chemistry results in superior mechanical properties, particularly fracture toughness and fatigue crack growth resistance, compared to the standard 2024 alloy. --- #### **2. Physical Properties** | Property | Value / Description | | :--- | :--- | | **Density** | 2.78 g/cm³ (0.100 lb/in³) | | **Melting Range** | ~ 500°C - 638°C (930°F - 1180°F) | | **Electrical Conductivity** | ~ 30-35% IACS (International Annealed Copper Standard) | | **Thermal Conductivity** | ~ 121 W/m·K | | **Coefficient of Thermal Expansion** | ~ 23.2 x 10⁻⁶/°C (20-100°C) | --- #### **3. Mechanical Properties (Typical for T3/T4 Temper)** 2024A is most commonly used in the T3 (solution heat-treated, cold worked, and naturally aged) or T4 (solution heat-treated and naturally aged) temper for sheet and plate. | Temper | Tensile Strength | Yield Strength (0.2% Offset) | Elongation (% in 50mm) | | :--- | :--- | :--- | :--- | | **2024A-T3** | min. 440 MPa (64 ksi) | min. 290 MPa (42 ksi) | min. 10-15% | | **2024A-T4** | min. 425 MPa (62 ksi) | min. 275 MPa (40 ksi) | min. 12-15% | *Note: The T3 temper, which includes a cold-working step after solution heat treatment, typically offers slightly higher strength than the T4 temper.* --- #### **4. International Standards** 2024A Aluminum Alloy is widely specified in European and international aerospace standards. | Standard System | Alloy Designation | Common Tempers | | :--- | :--- | :--- | | **EN (Europe)** | **EN AW-2024A** | T3, T4, T351 | | **ASTM (USA)** | **2024** (Note: The "A" variant is more specific to EN standards, but equivalent properties are specified) | T3, T4, T351 | | **AMS (Aerospace)** | **AMS 4037** (Sheet) | T3 | | **UNS (USA)** | **A92024** | - | --- #### **5. Product Applications** 2024A is a cornerstone material in the aerospace industry due to its excellent combination of strength and damage tolerance. * **Aerospace & Aviation (Primary Application):** * **Aircraft Skin and Fuselage:** Lower wing and fuselage skins where tension and fatigue loads are critical. * **Structural Components:** Wing ribs, bulkheads, and stringers. * **Cowlings and Fairings:** Non-critical structural covers and panels. * **Rivets:** Supplied in wire form for high-strength rivets (in W temper). * **Transportation:** * Military vehicle structures * High-performance racing car chassis and components * **Other Engineering:** * Various high-stress structural parts requiring a good strength-to-weight ratio. --- #### **6. Key Advantages & Considerations** * **Advantages:** * **High Strength-to-Weight Ratio:** Excellent specific strength, making it ideal for weight-critical structures. * **Good Fatigue Performance:** Resists crack initiation under cyclic loading. * **Excellent Damage Tolerance:** The modified composition provides better fracture toughness and resistance to fatigue crack growth compared to standard 2024. * **Good Machinability:** In the T3/T4 temper, it machines to a good surface finish. * **Considerations:** * **Poor Corrosion Resistance:** Like other Al-Cu alloys, it has very poor resistance to corrosion, especially in saline environments. It is almost always used in an **Alclad** form, where a thin layer of pure aluminum or a corrosion-resistant alloy is metallurgically bonded to the surface. * **Not Weldable:** It is generally considered non-weldable by common fusion welding techniques due to high susceptibility to solidification cracking and severe loss of properties in the heat-affected zone. Structures are primarily joined by riveting or bonding. * **Susceptible to Stress-Corrosion Cracking (SCC) in Short-Transverse Direction:** Thick plate material requires careful consideration of grain direction and stress paths to mitigate this risk. **Conclusion** 2024A Aluminum Alloy is a refined and optimized version of the legendary 2024, setting the standard for high-strength, damage-tolerant aerospace structures. Its improved chemistry, featuring zirconium and tighter impurity controls, delivers the enhanced reliability and performance demanded by modern aircraft design. While it requires careful handling regarding corrosion protection and joining, its unparalleled combination of strength, toughness, and fatigue resistance ensures its continued status as a fundamental material in aerospace engineering.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1531 gallon liquid totes Special package is available on request.