2017-T4; 2017-T451 Aluminum alloy,Aluminum 2017-T4; 2017-T451 alloy,E FORU

### **2017-T4 / 2017-T451 Aluminum Alloy Product Introduction** **Overview** 2017-T4 and 2017-T451 are high-strength, heat-treatable aluminum-copper alloys in their most commonly used tempers. These designations represent the alloy in a **solution heat-treated and naturally aged** condition. The T4 temper provides an excellent combination of high strength, good ductility, and outstanding machinability, making it a classic choice for high-performance structural components. The T451 temper is a stress-relieved version of T4, specifically for extruded rods and bars, offering improved dimensional stability for precision machining. --- #### **1. Chemical Composition (Typical Weight %)** The chemical composition is identical for all tempers of 2017 alloy, including T4 and T451. | Element | Minimum (%) | Maximum (%) | Notes | | :--- | :--- | :--- | :--- | | **Aluminum (Al)** | Balance | Balance | - | | **Copper (Cu)** | 3.5 | 4.5 | Primary strengthening element (forms CuAl₂ precipitates) | | **Magnesium (Mg)** | 0.40 | 0.8 | Secondary strengthening element | | **Manganese (Mn)** | 0.40 | 1.0 | Controls grain structure and improves strength | | **Silicon (Si)** | 0.20 | 0.8 | Impurity, but contributes to strength | | **Iron (Fe)** | - | 0.7 | Impurity | | **Zinc (Zn)** | - | 0.25 | Impurity | | **Chromium (Cr)** | - | 0.10 | Impurity | | **Others (Each)** | - | 0.05 | - | | **Others (Total)** | - | 0.15 | - | **Key Point:** The high Copper content is the primary source of strength through the formation of precipitates during natural aging. This same characteristic reduces corrosion resistance compared to other series like 6xxx. --- #### **2. Physical Properties** The physical properties are consistent across all tempers of 2017 alloy. | Property | Value / Description | | :--- | :--- | | **Density** | 2.79 g/cm³ (0.101 lb/in³) | | **Melting Range** | ~ 510°C - 640°C (950°F - 1185°F) | | **Electrical Conductivity** | ~ 34-40% IACS (International Annealed Copper Standard) | | **Thermal Conductivity** | ~ 134 W/m·K | | **Coefficient of Thermal Expansion** | ~ 23.6 x 10⁻⁶/°C (20-100°C) | --- #### **3. Mechanical Properties (Typical for T4 & T451 Tempers)** These tempers offer a robust combination of strength and workability. | Temper | Tensile Strength | Yield Strength (0.2% Offset) | Elongation (% in 50mm) | Hardness | | :--- | :--- | :--- | :--- | :--- | | **2017-T4** | min. 345 MPa (50 ksi) | min. 215 MPa (31 ksi) | min. 12-15% | ~ 105 HB | | **2017-T451** | min. 345 MPa (50 ksi) | min. 215 MPa (31 ksi) | min. 12-15% | ~ 105 HB | * **Temper Explanation:** * **-T4:** Solution heat-treated and naturally aged to a substantially stable condition. * **-T451:** A specific subset of T4. The "51" suffix indicates that the product has been stress-relieved by stretching to improve dimensional stability after solution heat treatment, which is critical for extruded bars and rods to prevent warping during heavy machining. --- #### **4. International Standards** 2017 Aluminum Alloy in T4 and T451 tempers is recognized under major international standards. | Standard System | Alloy Designation | Common Tempers | | :--- | :--- | :--- | | **ISO** | **AlCu4MgSi** | T4 | | **ASTM (USA)** | **2017** | T4, T451 | | **EN (Europe)** | **EN AW-2017A** | T4 | | **UNS (USA)** | **A92017** | - | | **JIS (Japan)** | **A2017** | T4 | --- #### **5. Product Applications** Thanks to its high strength-to-weight ratio and excellent machinability, 2017-T4/T451 is widely used in aerospace and high-performance engineering applications. * **Aerospace & Aviation:** * Aircraft structural components (frames, ribs) * Truck and trailer structural parts * Screw machine products (fittings, fasteners) * Rivets (historically very important) * **Automotive and Transportation:** * High-strength bolts, shafts, and gears * Suspension components * Drive train parts * **General Engineering and Machinery:** * Gears and pinions * Valve bodies and parts * Pump components * Various high-strength, machined parts requiring stability --- #### **6. Key Advantages & Considerations** * **Advantages:** * **High Strength:** Offers one of the highest strengths among aluminum alloys in the naturally aged (T4) condition. * **Excellent Machinability:** In the T4 temper, it machines exceptionally well, producing small chips and a good surface finish. It is considered to have superior machinability compared to many other high-strength alloys. * **Good Strength-to-Weight Ratio.** * **Stability of T451:** The T451 temper is preferred for complex machining jobs as it minimizes the risk of part distortion after machining. * **Considerations:** * **Poor Corrosion Resistance:** The high copper content makes it very susceptible to corrosion, particularly in saltwater environments. It almost always requires a protective coating, such as **Alclad** or anodizing. * **Not Weldable:** It is generally considered non-weldable by fusion welding techniques due to its high susceptibility to solidification cracking and loss of properties in the heat-affected zone. * **Natural Aging:** After solution heat treatment, it continues to age at room temperature, which can lead to slight property and dimensional changes over time for very tight-tolerance parts. **Conclusion** 2017-T4 and 2017-T451 are premier high-strength structural alloys whose primary advantage lies in their ability to be precision-machined to a high-strength state. The T451 temper provides the dimensional stability required for the most demanding machining applications. While its poor corrosion resistance and non-weldability require careful design consideration, it remains a vital material in aerospace and other high-performance engineering fields where its specific combination of strength, machinability, and stability is paramount.

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 1526 gallon liquid totes Special package is available on request.