6066-T6; 6066-T651 Aluminum alloy,Aluminum 6066-T6; 6066-T651 alloy,E FORU

### **Aluminum 6066-T6 / T651 Alloy: Product Introduction** **Overview** Aluminum 6066-T6 and T651 represent the peak-aged temper conditions of the high-strength 6066 aluminum alloy. The **T6 temper** indicates material that has been **solution heat-treated and artificially aged** to achieve maximum strength and hardness, while the **T651 temper** specifically denotes material that has been **stress-relieved by stretching** after solution heat treatment before artificial aging. These are the highest strength tempers available for 6066 aluminum, offering an exceptional combination of **maximum strength, good corrosion resistance, and excellent structural capabilities**. --- #### **1. Chemical Composition (Weight %)** | Element | Minimum (%) | Maximum (%) | |---------|-------------|-------------| | Silicon (Si) | 0.9 | 1.8 | | Iron (Fe) | - | 0.50 | | Copper (Cu) | 0.7 | 1.2 | | Manganese (Mn) | 0.6 | 1.0 | | Magnesium (Mg) | 0.8 | 1.4 | | Chromium (Cr) | - | 0.40 | | Zinc (Zn) | - | 0.20 | | Titanium (Ti) | - | 0.20 | | Other (Each) | - | 0.05 | | Other (Total) | - | 0.15 | | **Aluminum (Al)** | **Balance** | | --- #### **2. Physical Properties** | Property | Metric Value | Imperial Value | |----------|--------------|----------------| | **Density** | 2.72 g/cm³ | 0.0982 lb/in³ | | **Melting Range** | 555-650 °C | 1031-1202 °F | | **Electrical Conductivity** | 35-40% IACS | 35-40% IACS | | **Thermal Conductivity** | 145-160 W/m·K | 840-930 BTU·in/(hr·ft²·°F) | | **Coefficient of Thermal Expansion** | 23.2 × 10⁻⁶/°C | 12.9 × 10⁻⁶/°F | | **Modulus of Elasticity** | 69.0 GPa | 10,007 ksi | --- #### **3. Mechanical Properties** **Typical Mechanical Properties for 6066-T6/T651:** | Property | T6 Temper | T651 Temper | |----------|-----------|-------------| | **Tensile Strength** | 395-430 MPa | 395-430 MPa | | **Yield Strength (0.2% Offset)** | 360-395 MPa | 360-395 MPa | | **Elongation (in 50mm)** | 8-12% | 8-12% | | **Hardness (Brinell)** | 110-120 HB | 110-120 HB | | **Shear Strength** | 240-260 MPa | 240-260 MPa | | **Fatigue Strength** | 125-140 MPa | 125-140 MPa | **Key Difference:** - **T651** includes stress-relieving by stretching (typically 1-3% permanent set) after solution heat treatment, providing superior dimensional stability for precision machining applications. --- #### **4. International Standards** * **ASTM Standards:** * ASTM B221: Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes * ASTM B211: Standard Specification for Aluminum and Aluminum-Alloy Bar, Rod, and Wire * **AMS (Aerospace Material Specification):** * AMS 4159: 6066-T6 Sheet and Plate * AMS 4160: 6066-T651 Plate * AMS 4161: 6066-T651 Extrusions * **European Standards (EN):** * EN 573-3: Chemical composition * EN 755-2: Mechanical properties for extruded products * **ISO Standards:** * ISO 6361-2: Wrought aluminum and aluminum alloy sheets, strips and plates * ISO 6362-2: Wrought aluminum and aluminum alloy extruded rods/bars, tubes and profiles --- #### **5. Product Applications** **Aerospace & Defense:** - Aircraft structural components - Wing spars and ribs - Fuselage frames and longerons - Missile and defense system structures **Transportation Industry:** - High-performance automotive frames - Heavy truck chassis components - Railway vehicle structural members - Racing vehicle components **Marine Applications:** - Ship structural components - Marine platform structures - Offshore equipment components - Naval vessel structures **Industrial Applications:** - High-stress machinery frames - Industrial press components - Heavy equipment structures - Crane and lifting equipment --- #### **6. Key Characteristics & Advantages** * **Maximum Strength Capability:** Highest practical strength in the 6066 alloy system * **Excellent Strength-to-Weight Ratio:** Superior mechanical properties with lightweight characteristics * **Good Corrosion Resistance:** Adequate resistance for most environments * **Superior Fatigue Performance:** Excellent resistance to cyclic loading * **Dimensional Stability (T651):** Ideal for precision components requiring minimal distortion * **Good Machinability:** Can be machined to precise tolerances with proper techniques * **Adequate Weldability:** Can be welded using qualified procedures --- #### **7. Heat Treatment Specification** **Solution Heat Treatment:** - Temperature: 525-535°C (977-995°F) - Time: 30-60 minutes depending on thickness - Quenching: Rapid water quenching **Stress Relieving (T651):** - Method: Controlled stretching (1-3% permanent set) - Equipment: Precision stretching machinery **Artificial Aging:** - Temperature: 155-165°C (311-329°F) - Time: 8-12 hours - Control: Precise temperature and time monitoring --- #### **8. Processing and Fabrication** **Machining Characteristics:** - Good machinability with carbide tooling - Requires appropriate cutting parameters - Good surface finish achievable - Suitable for precision machining operations **Forming Limitations:** - Limited formability due to high strength - Suitable only for minor straightening - Specialized equipment required for any forming - High springback characteristics **Joining Methods:** - Weldable using TIG and MIG methods - Requires qualified welding procedures - Post-weld heat treatment recommended - Mechanical fastening preferred for critical applications **Surface Treatment Compatibility:** - Good for anodizing applications - Suitable for powder coating - Chemical conversion coatings applicable - Maintains surface integrity with proper treatment --- #### **9. Quality Assurance and Standards Compliance** **Testing Requirements:** - Comprehensive mechanical property testing - Chemical composition verification - Microstructural examination - Non-destructive testing as required **Certification:** - Mill test certificates per international standards - Process control documentation - Full traceability records - Third-party inspection available --- **Technical Note:** Aluminum 6066-T6/T651 represents the highest strength achievement within the 6066 alloy system, offering mechanical properties that approach some lower-grade 2xxx series alloys while maintaining better corrosion resistance. The T651 temper is particularly valuable for applications requiring extensive machining, as the stress-relieving process ensures dimensional stability during manufacturing. This combination of high strength, good corrosion resistance, and excellent fatigue performance makes 6066-T6/T651 invaluable for critical structural applications in aerospace, defense, transportation, and heavy industry where maximum performance is required.

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 2014 gallon liquid totes Special package is available on request.