6061-T4; 6061-T451 Aluminum alloy,Aluminum 6061-T4; 6061-T451 alloy,E FORU

### **6061-T4 / T451 Aluminum Alloy: Product Introduction** **Overview** 6061-T4 and T451 are intermediate temper conditions of the versatile 6061 aluminum-magnesium-silicon alloy. The **T4 temper** indicates material that has been **solution heat-treated and naturally aged** to a substantially stable condition. 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) | 0.40 | 0.8 | | Iron (Fe) | - | 0.7 | | Copper (Cu) | 0.15 | 0.40 | | Manganese (Mn) | - | 0.15 | | Magnesium (Mg) | 0.8 | 1.2 | | Chromium (Cr) | 0.04 | 0.35 | | Zinc (Zn) | - | 0.25 | | Titanium (Ti) | - | 0.15 | | Other (Each) | - | 0.05 | | Other (Total) | - | 0.15 | | **Aluminum (Al)** | **Balance** | | --- #### **2. Physical Properties** | Property | Typical Metric Value | Imperial Value | | :--- | :--- | :--- | | **Density** | 2.70 g/cm³ | 0.0975 lb/in³ | | **Melting Range** | 580 - 650 °C | 1075 - 1200 °F | | **Electrical Conductivity** | 45-48% IACS | 45-48% IACS | | **Thermal Conductivity** | 160-180 W/m·K | 930-1045 BTU·in/(hr·ft²·°F) | | **Coefficient of Thermal Expansion** | 23.6 × 10⁻⁶/°C | 13.1 × 10⁻⁶/°F | --- #### **3. Mechanical Properties** **Typical Mechanical Properties:** | Property | T4 Temper | T451 Temper | | :--- | :--- | :--- | | **Tensile Strength** | 205-240 MPa (30-35 ksi) | 205-240 MPa (30-35 ksi) | | **Yield Strength (0.2% Offset)** | 110-145 MPa (16-21 ksi) | 110-145 MPa (16-21 ksi) | | **Elongation (in 50mm)** | 16-22% | 16-22% | | **Hardness (Brinell)** | 60-70 HB | 60-70 HB | | **Shear Strength** | 125-165 MPa (18-24 ksi) | 125-165 MPa (18-24 ksi) | **Key Difference:** - **T451** includes stress-relieving by stretching (typically 1-3% permanent set) to minimize residual quenching stresses, providing better dimensional stability for machining --- #### **4. International Standards** * **ASTM (USA):** * ASTM B209: Sheet and Plate * ASTM B211: Bar, Rod, and Wire (T4 temper) * ASTM B221: Extruded Bars, Rods, Profiles, and Tubes * ASTM B210: Drawn Seamless Tubes * **AMS (Aerospace Material Specification):** * AMS 4115: 6061-T4 Sheet and Plate * AMS 4116: 6061-T451 Plate * **ISO (International Organization for Standardization):** * ISO 6361-2: Wrought aluminum sheets * ISO 6362-2: Extruded products * **EN (European Standards):** * EN 573-3: Chemical composition * EN 755-2: Extruded products --- #### **5. Product Applications** **Aerospace Applications:** - Aircraft fuselage skins and formers - Wing components requiring subsequent forming - Interior structural members - Bulkheads and frames (T451 for machined parts) **Transportation Industry:** - Truck and trailer body panels - Rail vehicle components - Automotive structural parts **Marine Applications:** - Boat hull components - Superstructure elements - Marine hardware **General Manufacturing:** - Complex formed brackets and supports - Pressure vessels - Structural components requiring post-forming aging - Prototype development parts --- #### **6. Key Characteristics & Advantages** * **Optimal Formability:** Maintains excellent ductility while providing substantially higher strength than O temper * **Good Strength-to-Weight Ratio:** Intermediate strength suitable for many structural applications * **Age-Hardenable:** Can be artificially aged to T6 temper for higher strength after forming operations * **Dimensional Stability (T451):** Stress-relieved temper minimizes distortion during machining * **Excellent Corrosion Resistance:** Maintains the good corrosion resistance of 6061 series * **Good Weldability:** All common welding methods can be employed * **Machinability:** Good machining characteristics in both tempers --- #### **7. Heat Treatment and Aging Characteristics** * **Solution Heat Treatment:** 530°C (985°F) for sufficient time followed by rapid quenching * **Natural Aging:** At room temperature, reaches substantial stability in 4-7 days * **Artificial Aging Potential:** Can be aged at 160-180°C (320-355°F) to achieve T6 properties * **Final Properties after Aging:** Tensile strength: 310 MPa (45 ksi), Yield strength: 276 MPa (40 ksi) **Technical Note:** The T4/T451 condition is particularly valuable for manufacturers who need to perform significant forming operations before achieving final high strength properties through artificial aging.

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 1994 gallon liquid totes Special package is available on request.