8091 Aluminum alloy,Aluminum 8091 alloy，E FORU

### **Aluminum 8091 Alloy Technical Datasheet** --- #### **1. Product Overview** **Aluminum 8091** is an advanced aluminum-lithium alloy belonging to the third generation of Al-Li alloys, specifically designed for aerospace applications requiring superior combination of strength, stiffness, and damage tolerance. This heat-treatable alloy offers significant weight savings compared to conventional aluminum alloys while maintaining excellent mechanical properties and improved corrosion resistance. --- #### **2. Chemical Composition (Weight %)** | Element | Composition Range | Typical Value | |---------|-------------------|---------------| | Aluminum (Al) | Balance | ≥95.5% | | Lithium (Li) | 2.4 - 2.9% | 2.65% | | Copper (Cu) | 1.6 - 2.2% | 1.9% | | Magnesium (Mg) | 0.7 - 1.3% | 1.0% | | Zirconium (Zr) | 0.08 - 0.16% | 0.12% | | Iron (Fe) | ≤ 0.15% | 0.08% | | Silicon (Si) | ≤ 0.10% | 0.05% | | Zinc (Zn) | ≤ 0.10% | 0.05% | | Manganese (Mn) | ≤ 0.05% | 0.02% | | Other Elements (each) | ≤ 0.05% | - | | Total Other Elements | ≤ 0.15% | - | **Key Composition Features:** - Higher lithium content for maximum density reduction - Enhanced copper content for improved strength - Zirconium for grain structure control and recrystallization inhibition - Optimized magnesium for precipitation strengthening - Ultra-low impurity levels for enhanced toughness --- #### **3. Physical Properties** | Property | Metric Value | Imperial Value | |----------|--------------|----------------| | Density | 2.53 g/cm³ | 0.091 lb/in³ | | Melting Range | 595-650°C | 1103-1202°F | | Thermal Conductivity | 80-88 W/m·K | - | | Electrical Conductivity | 16-20% IACS | - | | Modulus of Elasticity | 79 GPa | 11.5 × 10⁶ psi | | Coefficient of Thermal Expansion | 22.3 × 10⁻⁶/°C | 12.4 × 10⁻⁶/°F | | Specific Heat Capacity | 925 J/kg·K | - | | Electrical Resistivity | 86-108 nΩ·m | - | --- #### **4. Mechanical Properties** **Typical Properties in T851 Temper:** - **Tensile Ultimate Strength**: 490-550 MPa (71-80 ksi) - **Tensile Yield Strength (0.2% Offset)**: 420-480 MPa (61-70 ksi) - **Elongation in 50 mm**: 6-10% - **Shear Strength**: 290-330 MPa (42-48 ksi) - **Hardness (Vickers)**: 150-170 HV - **Fatigue Strength** (R=0.1, 5×10⁸ cycles): 190-220 MPa (28-32 ksi) - **Compressive Yield Strength**: 400-460 MPa (58-67 ksi) - **Fracture Toughness (K Ic)**: 25-29 MPa√m - **Bearing Strength**: 720-780 MPa (104-113 ksi) --- #### **5. International Standards** **Primary Specifications:** - **AMS 4252**: Aluminum Alloy 8091 Plate and Sheet - **EN 573-3**: Aluminum and aluminum alloys - Chemical composition - **ISO 209**: Wrought aluminum and aluminum alloys - **GB/T 3190**: Wrought aluminum and aluminum alloy chemical composition **Aerospace Standards:** - **ASTM B909**: Standard Guide for Aluminum Lithium Alloys - **MIL-HDBK-5**: Metallic Materials and Elements for Aerospace Vehicle Structures - **ABD 0031**: Airbus Technical Specification - **BMS 7-336**: Boeing Material Specification --- #### **6. Product Applications** **Aircraft Primary Structures:** - Upper and lower wing skins - Fuselage panels and stringers - Wing spar components - Bulkheads and frames - Empennage structures **Space and Defense Applications:** - Spacecraft primary structures - Satellite structural components - Missile airframes and components - Military aircraft structural members - Defense system components **High-Performance Components:** - Helicopter airframe components - Racing vehicle structural parts - High-performance sporting equipment - Advanced transportation systems - Specialized engineering structures --- #### **7. Key Characteristics** **Advantages:** - **9% Density Reduction** compared to conventional aluminum alloys - **11% Higher Stiffness** - **Excellent Strength-to-Weight Ratio** - **Good Damage Tolerance** - **Improved Corrosion Resistance** - **Superior Fatigue Performance** **Performance Benefits:** - Maximum weight savings among Al-Li alloys - Enhanced specific properties - Good combination of strength and toughness - Suitable for critical aerospace applications - Proven service performance --- #### **8. Processing Characteristics** **Heat Treatment:** - **Solution Treatment**: 525-535°C (977-995°F) - **Quenching**: Rapid quenching required - **Aging Treatment**: 155-165°C (311-329°F) for 20-30 hours **Machining:** - Moderate machinability rating: 35% - Requires sharp carbide tooling - Recommended cutting speed: 75-160 m/min - Special attention to tool geometry and cooling - Good surface finish achievable with proper techniques **Forming and Joining:** - **Limited Formability** in peak-aged tempers - **Excellent Friction Stir Welding** capability - **Good Adhesive Bonding** characteristics - **Mechanical Fastening** - good performance - **Specialized Processes** required for optimal results --- #### **9. Corrosion Resistance** **Performance Characteristics:** - **Atmospheric Corrosion**: Good resistance - **Stress Corrosion Cracking**: Moderate resistance - **Exfoliation Corrosion**: Fair to good resistance - **Galvanic Corrosion**: Requires proper isolation - **Overall Performance**: Suitable for aerospace environments **Protection Methods:** - Chemical conversion coatings - Primer and paint systems - Clad versions for improved corrosion resistance - Proper material selection for mating components - Regular inspection and maintenance --- #### **10. Quality Assurance** **Testing Requirements:** - Chemical composition verification - Mechanical property testing - Fracture toughness evaluation - Fatigue testing - Corrosion resistance testing - Non-destructive testing **Specialized Testing:** - Differential Scanning Calorimetry for phase analysis - Transmission Electron Microscopy for microstructure - Small-angle X-ray scattering for precipitate analysis - Fatigue crack growth rate testing --- #### **11. Comparison with Other Al-Li Alloys** | Property | 8091-T851 | 8090-T851 | 2090-T83 | |----------|------------|------------|-----------| | Density (g/cm³) | 2.53 | 2.54 | 2.59 | | Tensile Strength (MPa) | 490-550 | 470-530 | 455-515 | | Yield Strength (MPa) | 420-480 | 400-460 | 395-455 | | Lithium Content (%) | 2.4-2.9 | 2.2-2.7 | 1.9-2.6 | --- #### **Conclusion** Aluminum 8091 alloy represents the pinnacle of aluminum-lithium alloy development, offering the highest lithium content among commercially available Al-Li alloys and consequently the greatest density reduction. This advanced alloy provides aerospace engineers with exceptional weight-saving potential while maintaining high strength, good damage tolerance, and adequate corrosion resistance. While requiring specialized processing and careful attention to manufacturing techniques, 8091 delivers unparalleled specific properties that make it ideal for weight-critical aerospace applications. The alloy's proven performance in demanding applications continues to make it a valuable choice for advanced aerospace structures where maximum weight reduction is essential without compromising structural integrity and performance reliability.

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 2263 gallon liquid totes Special package is available on request.