Udimet 710 Nickel Alloy,ATG W4，1

### **Technical Datasheet: Udimet® 710 & ATG W4** **High-Performance Nickel-Based Superalloys for Turbine Blade Applications** --- ### **1. Udimet® 710 (UNS N07710)** #### **Overview** Udimet 710 is a high-strength, precipitation-hardenable nickel-based superalloy specifically developed for investment castings in the hottest sections of gas turbine engines. It is characterized by an outstanding combination of **creep-rupture strength**, **thermal fatigue resistance**, and good **oxidation resistance** at temperatures up to 980°C (1800°F). While primarily a casting alloy, it is also available in wrought forms like bar and billet for forging. Its balanced composition provides exceptional long-term microstructural stability, making it a classic choice for first-stage turbine blades and vanes in both aerospace and industrial gas turbines. #### **Chemical Composition (Typical Weight %)** | Element | Content (%) | Role in the Alloy | | :--- | :--- | :--- | | **Nickel (Ni)** | Balance | Austenitic matrix. | | **Chromium (Cr)** | ~18.0 | Confers oxidation and hot corrosion resistance. | | **Cobalt (Co)** | ~15.0 | Solid solution strengthener. | | **Molybdenum (Mo)** | ~3.0 | Solid solution strengthener. | | **Aluminum (Al)** | ~2.5 | Forms the primary strengthening γ' phase (Ni₃Al). | | **Titanium (Ti)** | ~5.0 | Forms the primary strengthening γ' phase (Ni₃Ti). | | **Tungsten (W)** | ~1.5 | Solid solution strengthener. | | **Carbon (C)** | ~0.07 | Forms carbides (MC, M₂₃C₆) for grain boundary strength. | | **Boron (B)** | ~0.020 | Enhances creep ductility and grain boundary strength. | | **Zirconium (Zr)** | ~0.05 | Further improves creep resistance. | #### **Physical & Mechanical Properties (Typical)** * **Density:** 8.05 g/cm³ (0.291 lb/in³) * **Melting Range:** ~1260 - 1335 °C (~2300 - 2435 °F) * **Room Temperature Tensile Strength (Aged):** * Ultimate Tensile Strength (UTS): > 1030 MPa (150 ksi) * Yield Strength (0.2% YS): > 795 MPa (115 ksi) * Elongation: > 8% * **Key Feature:** Superior and balanced creep-rupture life and ductility at 870°C - 980°C (1600°F - 1800°F). #### **Heat Treatment** A standard heat treatment involves a high-temperature solution treatment followed by a two-stage aging process to optimize the size and distribution of the γ' precipitates for maximum high-temperature strength and stability. #### **Product Applications** * **Investment Cast Turbine Blades and Nozzle Guide Vanes** (its primary application) * Turbine disks (forged from wrought stock) * Other static and rotating components in the high-pressure turbine section. #### **International Standards** * **AMS:** AMS 5392 (Investment Castings) * **UNS:** N07710 * **Werkstoff Nr.:** 2.4969 (Note: Can be shared with other alloys; chemical composition is the definitive identifier). --- ### **2. ATG W4** #### **Overview** **ATG W4** is a proprietary material specification, almost certainly from **Safran Aircraft Engines**. The "ATG" prefix is Safran's designation for material and process specifications. Similar to ATG W3, **"W4" defines a specific, controlled version of a high-performance nickel-based superalloy** intended for the most critical rotating components. Based on the naming convention and industry usage, ATG W4 is understood to be a specification for a **very high-strength forging alloy**, most notably **Udimet 720 (U720)** or an advanced derivative of it. This alloy is engineered for an optimal combination of ultra-high tensile strength, low-cycle fatigue (LCF) resistance, and damage tolerance, making it ideal for modern turbine disks. #### **Typical Characteristics (Inferred for U720Li Base)** * **Alloy Base:** Nickel-Chromium-Cobalt-Molybdenum-Titanium-Aluminum superalloy. * **Key Property:** Excellent overall mechanical property balance, particularly **tensile strength** and **LCF life** at intermediate temperatures (500°C - 750°C). * **Form:** Supplied as vacuum induction melted (VIM) + vacuum arc remelted (VAR) or triple-melted billets for isothermal forging into near-net-shape components. #### **Chemical Composition (Representative - Based on Udimet 720Li)** *This is an example for a typical base alloy. The exact ATG W4 specification must be consulted for precise limits.* | Element | Representative % (for U720Li) | | :--- | :--- | | **Ni** | Balance | | **Cr** | ~16.0 | | **Co** | ~14.7 | | **Mo** | ~3.0 | | **W** | ~1.25 | | **Ti** | ~5.0 | | **Al** | ~2.5 | | **C** | ~0.025 | | **B** | ~0.025 | | **Zr** | ~0.035 | #### **Physical & Mechanical Properties (Representative)** * **Density:** ~8.05 g/cm³ * **Room Temperature Tensile Strength (Aged):** * UTS: > 1515 MPa (220 ksi) * YS: > 1170 MPa (170 ksi) * **Key Feature:** Best-in-class strength and fatigue performance for turbine rotors. #### **Product Applications** * **High-Pressure Turbine (HPT) Disks / Discs** * **Compressor Disks** (later stages) * **Shafts** * **Spinners** * Used in advanced Safran engines like the CFM LEAP. #### **Standards & Specifications** * **Primary Standard:** **Safran ATG W4** specification. This is the controlling document. * **Related Alloy Standards:** The base alloy (e.g., Udimet 720) is often covered by: * **AMS:** AMS 4082 (Bar, Forging Stock), AMS 4083 (Die Forgings) * **Proprietary:** Rolls-Royce RPS 705, etc. --- ### **Summary Comparison** | Feature | Udimet 710 | ATG W4 (Inferred) | | :--- | :--- | :--- | | **Primary Use** | **Turbine Blades & Vanes** (Cast) | **Turbine Disks** (Wrought, Forged) | | **Primary Strength** | Creep-Rupture & Thermal Fatigue | Tensile Strength & Low-Cycle Fatigue (LCF) | | **Temperature Focus** | Very High (870-980°C) | Intermediate-High (500-750°C) | | **Primary Form** | Investment Castings | Wrought Billet & Forgings | | **Defining Standard** | AMS 5392, UNS N07710 | **Safran ATG W4 Proprietary Spec** | **Disclaimer:** The information provided is for technical reference and comparison purposes. Properties are typical and can vary with product form, heat treatment, and manufacturing route. **ATG W4 is a proprietary specification, and its exact requirements are defined solely by Safran Aircraft Engines.** For design and procurement, the official, latest issue of the relevant material specification (AMS, ATG, etc.) must be consulted. Udimet is a registered trademark of Special Metals Corporation (a PCC company).

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