7475-T761 Aluminum alloy,Aluminum 7475-T761 alloy，E FORU

### **Aluminum 7475-T761 Alloy Technical Datasheet** --- #### **1. Product Overview** **7475-T761** is a high-strength aluminum alloy from the Al-Zn-Mg-Cu (7xxx) series, specifically designed for aerospace applications requiring superior combinations of strength, fracture toughness, and corrosion resistance. The T761 temper indicates the material has undergone solution heat treatment, stress-relieving by stretching (typically 1.5-3% permanent set for plate products), and artificial aging to achieve optimal mechanical properties with enhanced resistance to exfoliation corrosion. --- #### **2. Chemical Composition (Weight %)** | Element | Composition Range | Function | |---------|-------------------|----------| | Zinc (Zn) | 5.2 - 6.2% | Primary strengthening element | | Magnesium (Mg) | 1.9 - 2.6% | Forms strengthening precipitates | | Copper (Cu) | 1.2 - 1.9% | Enhances strength and corrosion resistance | | Chromium (Cr) | 0.18 - 0.25% | Controls grain structure | | Iron (Fe) | ≤ 0.12% | Impurity control for toughness | | Silicon (Si) | ≤ 0.10% | Impurity control | | Manganese (Mn) | ≤ 0.06% | Impurity control | | Titanium (Ti) | ≤ 0.05% | Grain refinement | | Other Elements | ≤ 0.05% each | - | | Aluminum (Al) | Balance | Base metal | --- #### **3. Physical Properties** | Property | Value | |----------|-------| | Density | 2.80 g/cm³ (0.101 lb/in³) | | Melting Range | 475-635°C (887-1175°F) | | Thermal Conductivity | 125-135 W/m·K | | Electrical Conductivity | 33-38% IACS | | Modulus of Elasticity | 71 GPa (10.3 × 10⁶ psi) | | Coefficient of Thermal Expansion | 23.4 × 10⁻⁶/°C (20-100°C) | | Specific Heat Capacity | 860 J/kg·K | --- #### **4. Mechanical Properties** **Typical Room Temperature Properties:** - **Tensile Ultimate Strength**: 500-530 MPa (72-77 ksi) - **Tensile Yield Strength (0.2% Offset)**: 430-460 MPa (62-67 ksi) - **Compressive Yield Strength**: 425 MPa (62 ksi) - **Elongation in 50 mm**: 12-14% - **Shear Strength**: 275 MPa (40 ksi) - **Fatigue Strength (R.R. Moore, 5×10⁸ cycles)**: 145 MPa (21 ksi) - **Fracture Toughness (K_Ic)**: 32-35 MPa√m - **Hardness (Brinell)**: 130-140 HB --- #### **5. International Standards** **Primary Specifications:** - **AMS 4204**: Aluminum Alloy 7475-T761 Plate and Sheet - **ASTM B209**: Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate - **ASTM B247M**: Standard Specification for Aluminum and Aluminum-Alloy Die Forgings, Hand Forgings, and Rolled Ring Forgings **International Equivalents:** - **ISO 6361-2**: Wrought aluminum and aluminum alloy sheets, strips and plates - **EN 485-2**: Aluminum and aluminum alloys - Sheet, strip and plate - **JIS H4000**: Aluminum and aluminum alloy sheets and plates - **GB/T 3880**: Wrought aluminum and aluminum alloy plates, sheets and strips (China) --- #### **6. Product Applications** **Aerospace & Defense:** - Aircraft wing skins and fuselage panels - Space vehicle structural components - Military aircraft bulkheads and frames - Helicopter structural members and transmission parts - Missile airframes and components **Transportation & Industrial:** - High-performance automotive structural components - Racing bicycle frames and components - Marine vessel structures - Nuclear energy components - Precision machinery and equipment --- #### **7. Key Characteristics** **Advantages:** - Excellent exfoliation corrosion resistance - Superior fracture toughness - Good stress corrosion cracking resistance - High strength-to-weight ratio - Enhanced fatigue performance - Good machinability in aged condition - Excellent dimensional stability **Limitations:** - Requires protective coatings in severe environments - Limited weldability compared to other aluminum alloys - Higher cost than standard 7xxx series alloys - Special handling required during processing --- #### **8. Processing Characteristics** **Machining:** - Good machinability rating: 75-80% (relative to 2011-T3=100%) - Recommended cutting tools: Carbide with positive rake angles - Cutting speeds: 120-250 m/min for turning operations - Use adequate cooling for optimal surface finish **Heat Treatment:** - Solution Heat Treatment: 470-490°C (878-914°F) - Quenching: Rapid water quench required - Aging Treatment: Two-stage aging process - Stress Relief: 1.5-3% stretching after solution treatment **Forming Operations:** - Good formability in annealed condition - Limited cold forming capability in T761 temper - Hot working temperature range: 350-450°C (662-842°F) --- #### **9. Corrosion Resistance** **Performance Characteristics:** - **Exfoliation Corrosion**: Rating EB per ASTM G34 - **Stress Corrosion Cracking**: Good resistance in short transverse direction - **Intergranular Corrosion**: Moderate to good resistance - **General Corrosion**: Requires protective coatings for severe environments **Protection Methods:** - Anodizing (Type I or II) - Chemical conversion coatings - Paint and primer systems - Cathodic protection when required --- #### **10. Quality Assurance** **Testing Requirements:** - Ultrasonic inspection per ASTM E114 - Exfoliation corrosion testing per ASTM G34 - Stress corrosion testing per ASTM G47 - Fracture toughness testing per ASTM E399 - Mechanical property verification - Microstructural examination **Certification:** - Mill certification to applicable standards - Full traceability to original heat lot - Third-party verification available - Compliance certificates for aerospace requirements --- #### **11. Comparison with Similar Tempers** | Property | T761 | T76 | T751 | |----------|------|-----|------| | Tensile Strength | High | Higher | Medium | | Corrosion Resistance | Very Good | Good | Excellent | | Fracture Toughness | Excellent | Very Good | Good | | Stress Relief | Stretched + Aged | Aged Only | Stretched + Aged | | Typical Applications | Aerospace structures | General aerospace | Marine applications | --- #### **Conclusion** 7475-T761 aluminum alloy represents an advanced material solution for applications demanding an optimal balance of high strength, exceptional fracture toughness, and good corrosion resistance. The specific T761 temper processing, including controlled stretching and aging, provides enhanced dimensional stability and consistent mechanical properties throughout thick sections. This alloy is particularly valuable for critical aerospace structures where damage tolerance, fatigue performance, and reliability are paramount. Its superior combination of properties makes it a preferred choice for next-generation aircraft components and other high-performance engineering applications requiring the utmost in material performance and durability.

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 2218 gallon liquid totes Special package is available on request.