7475-T76 Aluminum alloy,Aluminum 7475-T76 alloy，E FORU

### **Aluminum 7475-T76 Alloy Technical Datasheet** --- #### **1. Product Overview** **7475-T76** is a high-strength aluminum alloy from the Al-Zn-Mg-Cu (7xxx) series, heat-treated to provide an optimal balance of strength, fracture toughness, and corrosion resistance. The T76 temper indicates the material has undergone solution heat treatment and artificial aging to a specific level that provides improved resistance to exfoliation corrosion compared to T6 temper, while maintaining higher strength than T73-type tempers. --- #### **2. Chemical Composition (Weight %)** | Element | Minimum | Maximum | |---------|----------|----------| | Zinc (Zn) | 5.2 | 6.2 | | Magnesium (Mg) | 1.9 | 2.6 | | Copper (Cu) | 1.2 | 1.9 | | Chromium (Cr) | 0.18 | 0.25 | | Iron (Fe) | - | 0.12 | | Silicon (Si) | - | 0.10 | | Manganese (Mn) | - | 0.06 | | Titanium (Ti) | - | 0.05 | | Other Elements | - | 0.05 each | | Aluminum (Al) | Balance | - **Key Composition Features:** - Controlled iron and silicon limits for enhanced toughness - Zinc-magnesium-copper ratio optimized for corrosion resistance - Chromium addition for grain structure control --- #### **3. Physical Properties** | Property | Value | |----------|-------| | Density | 2.80 g/cm³ (0.101 lb/in³) | | Melting Range | 475-635°C (887-1175°F) | | Thermal Conductivity | 128 W/m·K | | Electrical Conductivity | 34-38% IACS | | Modulus of Elasticity | 71 GPa (10.3×10⁶ psi) | | Coefficient of Thermal Expansion | 23.2×10⁻⁶/°C | --- #### **4. Mechanical Properties** **Typical Values at Room Temperature:** - **Tensile Ultimate Strength**: 510-538 MPa (74-78 ksi) - **Tensile Yield Strength (0.2% Offset)**: 441-469 MPa (64-68 ksi) - **Compressive Yield Strength**: 434 MPa (63 ksi) - **Elongation**: 11-13% (in 50 mm) - **Shear Strength**: 283 MPa (41 ksi) - **Fatigue Strength**: 152 MPa (22 ksi) - **Fracture Toughness (K_Ic)**: 30-33 MPa√m - **Hardness**: 135-145 HB --- #### **5. International Standards** **Primary Specifications:** - **AMS 4204**: Aluminum Alloy 7475-T76 Sheet and Plate - **ASTM B209**: Standard Specification for Aluminum Alloy Sheet and Plate - **ASTM B247M**: Standard Specification for Aluminum Alloy Die 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 H4040**: Aluminum and Aluminum Alloy Bars and Wires --- #### **6. Product Applications** **Aerospace Applications:** - Aircraft lower wing skins - Fuselage stringers and frames - Spacecraft structural components - Helicopter transmission parts - Military aircraft structural members **Transportation & Industrial:** - High-speed train components - Marine vessel structures - High-performance automotive parts - Precision measuring instruments - Nuclear energy components --- #### **7. Key Characteristics** **Advantages:** - Excellent exfoliation corrosion resistance - Good stress corrosion cracking resistance - High strength-to-weight ratio - Superior fracture toughness - Good fatigue performance - Excellent machinability - Balanced mechanical properties **Limitations:** - Requires corrosion protection in severe environments - Not recommended for fusion welding - Higher cost than standard alloys - Limited availability in some product forms --- #### **8. Processing Characteristics** **Machining:** - Excellent machinability rating: 80% (relative to 2011-T3=100%) - Recommended cutting speeds: 150-300 m/min - Tool materials: Carbide or premium HSS - Chip formation: Short, broken chips **Heat Treatment:** - Solution Treatment: 480±5°C (896±9°F) - Quenching: Rapid water quench required - Aging: Single-stage aging at 120-130°C (248-266°C) - Typical aging time: 20-28 hours **Forming:** - Good cold forming characteristics - Hot working temperature: 350-450°C (662-842°F) - Annealing temperature: 410°C (770°F) --- #### **9. Corrosion Resistance** **Performance Ratings:** - **Exfoliation Corrosion**: Resistance rating EB (Per ASTM G34) - **Stress Corrosion Cracking**: Good resistance in T76 temper - **Intergranular Corrosion**: Moderate resistance - **General Corrosion**: Requires protective coatings **Protection Methods:** - Anodizing (chromic or sulfuric acid) - Chemical conversion coating - Paint and primer systems - Cathodic protection --- #### **10. Quality Assurance & Testing** **Mandatory Testing:** - Ultrasonic inspection per ASTM E114 - Corrosion testing per ASTM G34 and G47 - Mechanical property verification - Fracture toughness testing (when specified) **Certification Requirements:** - Mill test certificate to applicable standards - Heat lot traceability - Chemical analysis report - Mechanical test reports --- #### **Comparison with Other Tempers** | Property | T76 | T6 | T73 | |----------|-----|----|-----| | Tensile Strength | High | Highest | Medium | | Yield Strength | High | Highest | Medium | | Corrosion Resistance | Good | Poor | Excellent | | Fracture Toughness | Excellent | Good | Very Good | | Typical Use | Balanced properties | Maximum strength | Maximum corrosion resistance | --- #### **Conclusion** 7475-T76 aluminum alloy provides an exceptional balance of high strength, excellent fracture toughness, and good corrosion resistance, making it ideally suited for aerospace structures and other high-performance applications. The T76 temper offers a superior combination of properties compared to both T6 and T73 tempers, delivering good corrosion resistance without significant strength sacrifice. This alloy is particularly valuable for applications requiring damage tolerance and durability in moderately corrosive environments, establishing it as a preferred choice for critical aircraft components and other demanding engineering applications.

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 2217 gallon liquid totes Special package is available on request.