7349 Aluminum alloy,Aluminum 7349 alloy，E FORU

### **Product Introduction: 7349 Aluminum Alloy** **Aluminum 7349** is a high-strength, heat-treatable wrought alloy from the **Al-Zn-Mg-Cu (7xxx series)** family. It is specifically designed to provide an exceptional combination of very high static strength and improved stress corrosion cracking (SCC) resistance, particularly in thick sections. This makes it a specialized choice for heavily loaded primary aerospace structures where both performance and durability are critical. --- ### **1. Chemical Composition** The composition of 7349 is carefully balanced to achieve its high strength and good damage tolerance, with controlled levels of major alloying elements and impurities. **Typical Composition (% by Weight)** | Element | Content | | :--- | :--- | | **Aluminum (Al)** | Balance | | **Zinc (Zn)** | 7.5 - 8.7 | | **Magnesium (Mg)** | 1.8 - 2.4 | | **Copper (Cu)** | 1.4 - 2.0 | | **Zirconium (Zr)** | 0.10 - 0.18 | | **Iron (Fe)** | ≤ 0.12 | | **Silicon (Si)** | ≤ 0.10 | | **Manganese (Mn)** | ≤ 0.05 | | **Chromium (Cr)** | ≤ 0.05 | | **Titanium (Ti)** | ≤ 0.05 | | **Other Impurities** | ≤ 0.05 each; ≤ 0.15 total | *Key Point: The high Zinc content (above 8%) is a primary driver for its very high strength. The use of Zirconium (Zr) as the primary grain refiner improves quench sensitivity, allowing for better through-thickness properties in thick plates.* --- ### **2. Physical Properties** The physical properties of 7349 are typical for high-strength 7xxx series alloys. | Property | Metric Value | Imperial Value | | :--- | :--- | :--- | | **Density** | ~2.85 g/cm³ | ~0.103 lb/in³ | | **Melting Range** | ~ 475 - 640 °C | ~ 887 - 1184 °F | | **Electrical Conductivity** | ~ 30-35% IACS | - | | **Thermal Conductivity** | ~ 130 W/m·K | - | | **Modulus of Elasticity** | 71 GPa | 10.3 x 10⁶ psi | --- ### **3. Mechanical Properties** 7349 is renowned for its high strength, which is comparable to or even exceeds that of 7055 and 7150 alloys, especially in thick sections. Properties are highly dependent on temper. **Typical Room Temperature Mechanical Properties (Thick Plate - T7651 Temper)** | Property | Value (Metric) | Value (Imperial) | | :--- | :--- | :--- | | **Tensile Ultimate Strength** | 655 - 690 MPa | 95 - 100 ksi | | **Tensile Yield Strength (0.2% Offset)** | 610 - 640 MPa | 88 - 93 ksi | | **Elongation at Break** | 8 - 11% | 8 - 11% | | **Hardness (Brinell)** | ~ 175 - 185 HB | ~ 175 - 185 HB | *Note: The T7651 temper is an over-aged condition that provides a much-improved resistance to exfoliation corrosion and stress corrosion cracking compared to the peak-strength T651 temper, with only a minor reduction in strength.* --- ### **4. International Standards** Aluminum 7349 is covered by several key international standards, primarily in the aerospace sector. * **Aerospace Material Specifications (AMS):** * **AMS 4345:** This is the primary specification for Aluminum Alloy 7349 Plate (solution heat treated, stress relieved, and artificially over-aged). This standard defines the requirements for aerospace applications. * **ASTM International:** * **ASTM B209:** Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate. 7349 would be included under this umbrella standard for its product form. * **European Standards (EN):** * It may be designated under **EN 485** (Sheet, strip and plate) but is most commonly specified and procured to the **AMS** standard for aerospace projects. * **OEM Standards:** It is often used against proprietary material specifications from major aerospace manufacturers like Airbus and Boeing. --- ### **5. Product Applications** 7349 is engineered for the most demanding structural applications, primarily in: * **Aerospace Structures:** * **Upper Wing Skins and Cover Plates:** Especially for large commercial and military aircraft, where high compressive strength is critical. * **Fuselage Frames and Bulkheads:** Providing high strength and damage tolerance in thick sections. * **Wing Spars and Stringers:** As a replacement for alloys like 7150 and 7050 where higher strength is required. * **Defense Applications:** * **Load-bearing components in military aircraft.** * **Structural parts for unmanned aerial vehicles (UAVs).** * **Other High-Performance Applications:** * Critical components in high-speed machining equipment. * Structures in motorsports where a supreme strength-to-weight ratio is needed. --- ### **6. Key Characteristics & Advantages** * **Very High Strength:** Offers one of the highest strength levels among commercially available aluminum alloys, particularly in thick sections. * **Good Resistance to Stress Corrosion Cracking (SCC):** The over-aged tempers (T76, T74) provide excellent SCC resistance, which is a critical improvement over peak-aged tempers. * **Good Fracture Toughness:** Provides a good balance between ultra-high strength and the ability to resist crack propagation. * **Excellent Property Consistency in Thick Sections:** The alloy chemistry and use of Zirconium minimize the loss of strength in the center of thick plates, a common issue known as quench sensitivity. ### **Considerations** * **Corrosion Resistance:** Like all high-strength 7xxx alloys, it requires protective coatings (e.g., anodizing, primer) for service in corrosive environments unless an over-aged temper is specified. * **Weldability:** Generally considered poor for fusion welding; components are typically joined using mechanical fasteners (rivets, bolts). * **Machinability:** It can be machined in the T7651 temper, but its high strength demands powerful machinery and wear-resistant tooling. * **Cost:** A premium, specialized alloy, it is more expensive than standard aerospace alloys due to its advanced composition and processing requirements. ### **Conclusion** **Aluminum 7349 alloy** is a superior-grade material that pushes the boundaries of aluminum structural performance. It is strategically used in applications where its exceptional strength in thick sections and improved corrosion resistance offer a significant advantage over other high-strength alloys like 7150 or 7050. Its primary role is in next-generation and heavily upgraded aerospace frames, enabling lighter, stronger, and more durable aircraft structures.

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 2210 gallon liquid totes Special package is available on request.