7049A Aluminum alloy,Aluminum 7049A alloy，E FORU

### **7049A Aluminum Alloy: High-Strength Forging Alloy** **7049A Aluminum Alloy** is a premium, heat-treatable alloy from the Al-Zn-Mg-Cu (7xxx) series, specifically known for its **very high strength and excellent stress corrosion cracking (SCC) resistance**. It was developed as an improved version of the 7049 alloy, with tighter control over impurities to enhance its toughness and performance consistency. 7049A is primarily used in the aerospace and defense industries for critical, heavily-loaded structural components, particularly in the form of forgings and thick plates. --- #### **1. Chemical Composition** The exceptional properties of 7049A are achieved through a carefully balanced and controlled chemical composition. The "A" variant typically implies lower impurity limits for improved toughness. | Element | Content (%) (Typical) | Role in the Alloy | | :--- | :--- | :--- | | **Zinc (Zn)** | 7.2 - 8.4 | Primary strengthening element; forms the main hardening precipitates (MgZn₂). | | **Magnesium (Mg)** | 2.0 - 2.9 | Co-operates with Zn to form the strengthening η' (MgZn₂) phase during aging. | | **Copper (Cu)** | 1.2 - 1.9 | Significantly enhances strength and dramatically improves resistance to stress corrosion cracking. | | **Chromium (Cr)** | 0.10 - 0.22 | Forms fine dispersoids that inhibit recrystallization and control grain structure, improving toughness. | | **Iron (Fe)** | ≤ 0.15 | **Tighter impurity control** to enhance fracture toughness. | | **Silicon (Si)** | ≤ 0.12 | **Tighter impurity control** to improve ductility and toughness. | | **Manganese (Mn)** | ≤ 0.20 | - | | **Titanium (Ti)** | ≤ 0.10 | - | | **Other Impurities** | ≤ 0.05 each; ≤ 0.15 total | - | | **Aluminum (Al)** | Balance | Base metal. | **Key Characteristics:** The high Copper content is a defining feature of 7049A, contributing directly to its superior strength and SCC resistance compared to many other 7xxx alloys. --- #### **2. Physical Properties** The physical properties of 7049A are consistent with other high-copper 7xxx series alloys. | Property | Value / Description | | :--- | :--- | | **Density** | ≈ 2.84 g/cm³ (0.102 lb/in³) | | **Melting Range** | ≈ 475°C - 635°C (887°F - 1175°F) | | **Electrical Conductivity** | ≈ 35-40% IACS (International Annealed Copper Standard) | | **Thermal Conductivity** | ≈ 105-125 W/m·K | | **Coefficient of Thermal Expansion** | ≈ 23.2 x 10⁻⁶/°C (20-100°C) | | **Modulus of Elasticity (E)** | ≈ 71 GPa (10.3 x 10⁶ psi) | --- #### **3. Mechanical Properties (Typical for T7351 Temper)** The T7351 temper (Solution Heat-Treated, Stress-Relieved by Stretching, and **Over-Aged**) is commonly specified to achieve the optimal balance of high strength and exceptional stress corrosion cracking resistance, especially for thick sections. | Property | Typical Value | | :--- | :--- | | **Tensile Strength (Ultimate)** | 530 - 570 MPa (77 - 83 ksi) | | **Tensile Yield Strength (0.2% Offset)** | 460 - 500 MPa (67 - 73 ksi) | | **Elongation (in 50 mm / 2 in)** | 8 - 11 % | | **Hardness (Brinell)** | ≈ 150 HB | *Note: In a T6 temper (peak-aged), strength can be significantly higher, but SCC resistance is lower.* --- #### **4. Product Applications** 7049A Aluminum Alloy is specified for the most demanding structural applications where its unique combination of properties is critical. * **Aerospace Industry (Primary Application):** * **Aircraft Landing Gear:** Forgings for beams, pistons, and support structures. * **Airframe Components:** Fuselage frames, wing spars, and bulkheads. * **Rocket and Missile Components:** Motor sections and structural rings. * **Defense Industry:** * **Armored Vehicle Components:** Hulls, turrets, and other structural parts. * **High-Performance Automotive:** * Suspension components and chassis parts in motorsports. --- #### **5. International Standards** 7049A is recognized by major aerospace and international standards bodies. | Standard Body | Alloy Designation | Common Forms | Relevant Standard | | :--- | :--- | :--- | :--- | | **Aluminum Association (AA)** | **7049A** | Forgings, Plate | AA Teal Sheets / ANSI H35.1 | | **Aerospace (AMS)** | **7049** | Forgings, Die Forgings | AMS 4124 (Forgings) / AMS 4127 (Die Forgings) | | **European Norm (EN)** | **EN AW-7049A** | Forgings | EN 586-2 (Forgings) | | **ASTM International** | **Aluminum 7049** | - | ASTM B247 (Forgings) | | **Unified Numbering System (UNS)** | **A97049** | - | SAE J1086 | --- #### **Key Advantages & Summary** * **Very High Strength:** Offers strength levels comparable to, and in some cases exceeding, 7075-T73, making it one of the strongest commercially available aluminum alloys. * **Excellent Stress Corrosion Cracking (SCC) Resistance:** The over-aged T73-type temper provides exceptional resistance to failure under tension in corrosive environments, a critical requirement for safety-critical components like landing gear. * **Good Fracture Toughness:** The controlled impurity levels (low Fe and Si) contribute to improved damage tolerance. * **Excellent Forgability:** Well-suited for producing complex, high-integrity forged components. In conclusion, **7049A Aluminum Alloy** is a specialized, ultra-high-strength material designed for the most critical applications. Its high copper content and availability in over-aged tempers make it the alloy of choice when the design demands **maximum strength coupled with superior stress corrosion cracking resistance**, particularly in the form of large forgings for the aerospace sector.

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 2143 gallon liquid totes Special package is available on request.