6066-T4; 6066-T451 Aluminum alloy,Aluminum 6066-T4; 6066-T451 alloy,E FORU

### **Aluminum 6066-T4 / T451 Alloy: Product Introduction** **Overview** Aluminum 6066-T4 and T451 are intermediate temper conditions of the high-strength 6066 aluminum alloy. The **T4 temper** indicates material that has been **solution heat-treated and naturally aged** to a substantially stable condition, while the **T451 temper** specifically denotes material that has been **stress-relieved by stretching** after solution heat treatment. These tempers provide an optimal balance of **good strength and excellent formability**, making them ideal for applications requiring significant forming operations before final aging or use. --- #### **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** | 38-42% IACS | 38-42% IACS | | **Thermal Conductivity** | 150-165 W/m·K | 870-955 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-T4/T451:** | Property | T4 Temper | T451 Temper | |----------|-----------|-------------| | **Tensile Strength** | 260-300 MPa | 260-300 MPa | | **Yield Strength (0.2% Offset)** | 150-180 MPa | 150-180 MPa | | **Elongation (in 50mm)** | 14-18% | 14-18% | | **Hardness (Brinell)** | 75-85 HB | 75-85 HB | | **Shear Strength** | 170-200 MPa | 170-200 MPa | | **Fatigue Strength** | 100-120 MPa | 100-120 MPa | **Key Difference:** - **T451** includes stress-relieving by stretching (typically 1-3% permanent set) to minimize residual quenching stresses, providing better dimensional stability for machining operations. --- #### **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 4157: 6066-T4 Sheet and Plate * AMS 4158: 6066-T451 Plate * **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 Applications:** - Aircraft structural components requiring forming - Wing and fuselage elements before final aging - Aerospace brackets and fittings - Interior structural members **Transportation Industry:** - Automotive structural components - Truck and trailer structural members - Railway vehicle components - Heavy vehicle frames **Industrial Applications:** - Machinery components requiring post-forming aging - Equipment frames and supports - Structural components for further processing - Heavy-duty industrial parts **Marine and Defense:** - Marine structural components - Defense equipment elements - Naval vessel components - Military vehicle parts --- #### **6. Key Characteristics & Advantages** * **High Strength Potential:** Significantly stronger than standard 6061-T4 * **Excellent Formability:** Maintains good ductility for forming operations * **Age-Hardenable:** Can be artificially aged to T6 temper for maximum strength * **Dimensional Stability (T451):** Stress-relieved temper minimizes distortion during machining * **Good Corrosion Resistance:** Maintains adequate corrosion resistance * **Excellent Weldability:** All common welding methods can be employed * **Good Machinability:** Can be machined using standard techniques --- #### **7. Heat Treatment and Aging Characteristics** **Solution Heat Treatment:** - Temperature: 525-535°C (977-995°F) - Time: 30-60 minutes depending on thickness - Quenching: Rapid water quenching **Natural Aging:** - Occurs at room temperature - Reaches substantial stability in 4-10 days - Provides stable mechanical properties **Artificial Aging Potential (to T6):** - Temperature: 155-165°C (311-329°F) - Time: 8-12 hours - Final Strength: 395-430 MPa tensile strength --- #### **8. Processing and Fabrication** **Forming Characteristics:** - Good for bending and moderate forming operations - Suitable for stretch forming - Adequate for roll forming applications - Moderate springback characteristics **Machining Properties:** - Good machinability in T4/T451 condition - Better chip control than annealed temper - Good surface finish achievable - Suitable for precision machining **Joining Methods:** - Excellent weldability using TIG and MIG methods - Good for resistance welding - Suitable for adhesive bonding - Mechanical fastening easily accomplished **Surface Treatment Compatibility:** - Good for anodizing after final heat treatment - Suitable for various coating applications - Good surface preparation characteristics - Maintains integrity with proper treatment --- #### **9. Quality Assurance** **Testing and Verification:** - Mechanical property testing - Chemical composition analysis - Dimensional stability verification (T451) - Surface quality inspection **Certification:** - Mill test certificates per international standards - Process control documentation - Traceability records - Compliance with industry specifications --- **Technical Note:** Aluminum 6066-T4/T451 offers a superior combination of strength and formability compared to other 6xxx series alloys in the same temper. The enhanced chemistry of 6066, with higher copper, silicon, and magnesium content, provides significantly higher strength potential while maintaining good workability. The T451 temper is particularly valuable for components that require extensive machining, as the stress-relieving process ensures dimensional stability during manufacturing. These tempers serve as an excellent intermediate condition for components that will undergo final aging to achieve the full high-strength potential of the 6066 alloy system.

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 2013 gallon liquid totes Special package is available on request.