706 Nickel Superalloy,UNS N09706; AMS 5605, 5606, 5701, 5702, 5703,,E FORU

### **Product Introduction: Alloy 706 (UNS N09706) Nickel-Iron-Based Superalloy** **Alloy 706** is a precipitation-hardenable nickel-iron-chromium superalloy renowned for its exceptional combination of high strength, good manufacturability, and excellent cost-effectiveness. It possesses outstanding machinability and weldability compared to many other high-strength superalloys, making it a preferred choice for large, complex components in gas turbine engines. Its strength is derived from the precipitation of gamma prime [γ'] and gamma double prime [γ''] phases during aging, similar to the mechanism in Alloy 718, but with a composition optimized for better machinability. This alloy maintains high tensile, creep, and rupture strength up to about 1300°F (705°C) and exhibits good resistance to oxidation and corrosion. It is a cornerstone material for rotating components in the aerospace and power generation industries. --- #### **1. Chemical Composition (Weight %)** The typical chemical composition of Alloy 706 per relevant AMS specifications is as follows: | Element | Content (%) | Element | Content (%) | | :--- | :--- | :--- | :--- | | **Nickel (Ni)** | 39.0 - 44.0 | **Niobium (Nb)** | 2.50 - 3.30 | | **Chromium (Cr)** | 14.50 - 17.50 | **Molybdenum (Mo)** | 0.20 - 0.80 | | **Iron (Fe)** | Balance | **Aluminum (Al)** | 0.20 - 0.40 | | **Titanium (Ti)** | 1.50 - 2.00 | **Silicon (Si)** | ≤ 0.35 | | **Manganese (Mn)**| ≤ 0.35 | **Sulfur (S)** | ≤ 0.015 | | **Carbon (C)** | ≤ 0.08 | **Phosphorus (P)** | ≤ 0.015 | | **Copper (Cu)** | ≤ 0.30 | **Boron (B)** | 0.003 - 0.010 | **Key Microstructure:** The high strength is achieved through a dual precipitation hardening mechanism. The primary strengthening phase is gamma double prime (γ''), Ni₃Nb, supplemented by the gamma prime (γ') phase, Ni₃(Al, Ti). --- #### **2. Physical Properties** Typical physical properties for Alloy 706 are provided below. | Property | Metric Units | Imperial Units | | :--- | :--- | :--- | | **Density** | 8.05 g/cm³ | 0.291 lb/in³ | | **Melting Range** | ~1370 - 1425 °C | ~2500 - 2600 °F | | **Specific Heat (20°C)** | 460 J/kg·K | 0.110 Btu/lb·°F | | **Thermal Conductivity (20°C)** | 13.0 W/m·K | 90 Btu·in/hr·ft²·°F | | **Mean Coefficient of Thermal Expansion (20-100°C)** | 13.5 μm/m·°C | 7.5 μin/in·°F | | **Modulus of Elasticity (Tensile)** | 205 GPa | 29.7 x 10⁶ psi | | **Electrical Resistivity** | 1.10 μΩ·m | - | --- #### **3. Mechanical Properties (Typical)** Mechanical properties are developed through a standard heat treatment sequence involving solution annealing and a double aging process. **Standard Heat Treatment:** * **Solution Anneal:** 1700°F - 1850°F (927°C - 1010°C), followed by rapid cooling. * **Aging:** 1550°F ± 25°F (843°C ± 14°C) for 3 hours, furnace cool to 1150°F (621°C), hold for 3 hours, then air cool. **Typical Room Temperature Mechanical Properties (After Full Heat Treatment):** | Property | Value (Typical Minimum) | | :--- | :--- | | **Tensile Strength** | 1100 MPa (160 ksi) | | **Yield Strength (0.2% Offset)** | 760 MPa (110 ksi) | | **Elongation (in 4D)** | 15% | | **Redraction of Area** | 20% | *Note: These are typical values; specific requirements vary by product form and AMS specification.* --- #### **4. International Standards & Specifications** Alloy 706 is primarily covered by a suite of Aerospace Material Specifications (AMS) from SAE International, which define requirements for different product forms. **Aerospace Material Specifications (AMS - SAE International):** * **AMS 5605:** Corrosion and heat-resistant steel, sheet, strip, and plate (706 Alloy). * **AMS 5606:** Corrosion and heat-resistant steel, bar and wire (706 Alloy). * **AMS 5701:** Nickel alloy, forgings (706 Alloy). * **AMS 5702:** Nickel alloy, bars and forgings (706 Alloy). * **AMS 5703:** Nickel alloy, investment castings (706 Alloy). **Other Key Standards:** * **UNS:** N09706 * **ASTM:** While less common than for Alloy 718, it can be supplied to equivalent properties per **ASTM B637** for bars and forgings. * **Proprietary Specifications:** Often supplied to OEM-specific standards from companies like GE, Pratt & Whitney, and SNECMA. --- #### **5. Product Applications** Alloy 706's unique blend of strength, fabricability, and cost-performance makes it ideal for large, complex structural components, particularly in gas turbine engines. * **Aerospace & Gas Turbines:** * **Low-Pressure Turbine Disks** (a primary application) * **Engine Shafts** (especially mid-shafts) * Compressor disks and rotors * Turbine casings and frames * Spacers and seals * **Power Generation:** * Turbine disks and blades for land-based gas turbines * Structural components in high-temperature sections --- #### **Summary of Key Advantages** * **Excellent High-Strength:** Offers high tensile, yield, and creep-rupture strength suitable for temperatures up to ~1300°F (705°C). * **Superior Machinability:** Notably easier to machine than Alloy 718, leading to reduced manufacturing time and cost for complex parts. * **Good Weldability:** Can be welded using common techniques without a strong tendency for post-weld cracking, a significant advantage over many other high-strength superalloys. * **Cost-Effective:** Lower nickel content and better machinability make it a more economical choice for large components where the supreme performance of Alloy 718 is not required. **Disclaimer:** The information provided here is for reference purposes. Specific properties and performance are dependent on the manufacturing process, heat treatment, and final product form. For critical applications, always consult the official material specifications and the alloy producer's data sheets.

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 3129 gallon liquid totes Special package is available on request.