7475-T7651 Aluminum alloy,Aluminum 7475-T7651 alloy，E FORU

### **Aluminum 7475-T7651 Alloy Technical Datasheet** --- #### **1. Product Overview** **7475-T7651** is a premium aerospace-grade aluminum alloy from the Al-Zn-Mg-Cu (7xxx) series, specifically designed for applications requiring an optimal balance of high strength, exceptional fracture toughness, and superior corrosion resistance. The T7651 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 a specific over-aged condition that provides excellent exfoliation corrosion resistance while maintaining high mechanical strength. --- #### **2. Chemical Composition (Weight %)** | Element | Composition | Function | |---------|-------------|----------| | Zinc (Zn) | 5.2 - 6.2% | Primary strengthening via precipitation | | Magnesium (Mg) | 1.9 - 2.6% | Forms η' and η phases (MgZn₂) | | Copper (Cu) | 1.2 - 1.9% | Enhances strength and corrosion resistance | | Chromium (Cr) | 0.18 - 0.25% | Grain refinement and recrystallization control | | Iron (Fe) | ≤ 0.12% | Controlled for toughness | | Silicon (Si) | ≤ 0.10% | Controlled for toughness | | Manganese (Mn) | ≤ 0.06% | Impurity control | | Titanium (Ti) | ≤ 0.05% | Grain refinement | | Other Elements | ≤ 0.05% each | Impurity control | | Aluminum (Al) | Balance | Matrix | --- #### **3. Physical Properties** | Property | Metric Value | Imperial Value | |----------|--------------|----------------| | Density | 2.80 g/cm³ | 0.101 lb/in³ | | Melting Range | 475-635°C | 887-1175°F | | Thermal Conductivity | 130 W/m·K | - | | Electrical Conductivity | 34-38% IACS | - | | Modulus of Elasticity | 71 GPa | 10.3 × 10⁶ psi | | Shear Modulus | 26.5 GPa | 3.84 × 10⁶ psi | | Poisson's Ratio | 0.33 | 0.33 | | Coefficient of Thermal Expansion | 23.4 × 10⁻⁶/°C | 13.0 × 10⁻⁶/°F | --- #### **4. Mechanical Properties** **Typical Room Temperature Properties:** - **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 in 50 mm**: 11-13% - **Shear Strength**: 283 MPa (41 ksi) - **Bearing Yield Strength** (e/D=2.0): 703 MPa (102 ksi) - **Bearing Ultimate Strength** (e/D=2.0): 924 MPa (134 ksi) - **Fatigue Strength** (R.R. Moore, 5×10⁸ cycles): 152 MPa (22 ksi) - **Fracture Toughness (K_Ic)**: 30-33 MPa√m - **Hardness (Brinell)**: 135-145 HB --- #### **5. International Standards** **Primary Specifications:** - **AMS 4201**: Aluminum Alloy 7475-T7651 Plate - **ASTM B209**: Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate - **ASTM B247M**: 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 H4040**: Aluminum and aluminum alloy bars, rods and wires - **GB/T 3880.2**: Wrought aluminum and aluminum alloy plates, sheets and strips (China) --- #### **6. Product Applications** **Aerospace Applications:** - Aircraft lower wing skins and cover plates - Fuselage frames and bulkheads - Spacecraft structural components - Helicopter transmission parts - Military aircraft structural members - Landing gear support components **Defense & Marine:** - Armored vehicle components - Missile structural parts - Naval vessel superstructures - Military bridge components **Industrial Applications:** - High-performance automotive chassis components - Racing bicycle frames and components - Nuclear energy components - Precision machinery frames - High-stress tooling applications --- #### **7. Key Characteristics** **Advantages:** - Excellent exfoliation corrosion resistance - Superior stress corrosion cracking resistance - High fracture toughness - Excellent strength-to-weight ratio - Good fatigue performance - Enhanced dimensional stability - Good machinability in aged condition **Limitations:** - Requires protective coatings in severe marine environments - Limited weldability without special procedures - Higher cost than conventional 7xxx alloys - Requires controlled machining practices --- #### **8. Processing Characteristics** **Machining:** - Machinability Rating: 80% (relative to 2011-T3=100%) - Recommended Tools: Carbide with positive rake angles - Cutting Speeds: 150-300 m/min for turning - Feed Rates: 0.15-0.30 mm/rev - Cooling: Water-soluble oils recommended **Heat Treatment:** - Solution Heat Treatment: 480°C ± 5°C (896°F ± 9°F) - Quenching: Rapid water quench required - Aging Treatment: 120-130°C (248-266°F) for 20-28 hours - Stress Relieving: 1.5-3% permanent stretch **Forming:** - Cold Working: Limited capability in T7651 condition - Hot Working Temperature: 350-450°C (662-842°F) - Annealing: 415°C (775°F) for 2-3 hours, furnace cool --- #### **9. Corrosion Resistance** **Performance Ratings:** - **Exfoliation Corrosion**: Resistance Rating EB (ASTM G34) - **Stress Corrosion Cracking**: Excellent (ASTM G47) - **Intergranular Corrosion**: Good resistance - **General Corrosion**: Requires protection in severe environments **Protection Methods:** - Anodizing (Type I - Chromic Acid) - Chemical Conversion Coating (Alodine) - Primer and Paint 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 Test Certificate to AMS 4201 - Heat Lot Traceability - Chemical Analysis Report - Mechanical Test Reports - Non-Destructive Testing Reports --- #### **11. Comparison with Similar Tempers** | Property | T7651 | T7351 | T651 | |----------|-------|-------|------| | Tensile Strength (MPa) | 510-538 | 483-510 | 524-552 | | Yield Strength (MPa) | 441-469 | 400-434 | 455-483 | | Exfoliation Corrosion | Excellent | Excellent | Poor | | Stress Corrosion | Excellent | Excellent | Fair | | Fracture Toughness | Excellent | Excellent | Good | --- #### **Conclusion** 7475-T7651 aluminum alloy represents the pinnacle of aluminum material technology for aerospace applications requiring an exceptional balance of high strength, superior damage tolerance, and excellent corrosion resistance. The specific T7651 temper processing, including controlled stretching and optimized aging, provides outstanding resistance to exfoliation and stress corrosion cracking while maintaining high mechanical properties. This combination makes it ideally suited for critical aircraft structures such as lower wing skins and fuselage components where reliability, durability, and safety are paramount. The alloy's consistent performance, stringent quality controls, and proven track record in aerospace applications establish it as a premier choice for next-generation aircraft designs 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 2219 gallon liquid totes Special package is available on request.