UDIMET alloy 520 Superalloy,PDS 15125A1，1

### **Product Datasheet: UDIMET® Alloy 520 (PDS 15125A1)** **A High-Strength, Precipitation-Hardenable Nickel-Based Superalloy** --- #### **1. Overview** UDIMET® Alloy 520 is a high-performance, wrought nickel-based superalloy strengthened by precipitation hardening. It is specifically engineered to exhibit an exceptional combination of high tensile strength, excellent creep resistance, and good corrosion/oxidation resistance at elevated temperatures. This alloy is primarily supplied in the form of billet and bar for machining into critical components subjected to extreme stress and temperature environments, particularly in aerospace and industrial gas turbine engines. The designation **PDS 15125A1** refers to the specific Product Data Sheet or material specification, often from a manufacturer or a large OEM (like GE Aviation, Safran, or Rolls-Royce), which details the precise manufacturing, quality, and testing requirements for the material. #### **2. Chemical Composition (Typical Weight %)** The chemical composition is critical for achieving the desired mechanical and physical properties. The typical composition of UDIMET 520 is as follows: | Element | Content (%) | Role in the Alloy | | :--- | :--- | :--- | | **Nickel (Ni)** | Balance | Forms the austenitic (face-centered cubic) matrix. | | **Chromium (Cr)** | ~19.0 | Provides resistance to oxidation and hot corrosion. | | **Cobalt (Co)** | ~12.0 | Solid solution strengthener; reduces the solubility of gamma prime. | | **Molybdenum (Mo)** | ~6.0 | Potent solid solution strengthener. | | **Aluminum (Al)** | ~2.0 | Forms the primary strengthening γ' phase (Ni₃Al). | | **Titanium (Ti)** | ~3.0 | Forms the primary strengthening γ' phase (Ni₃Ti). | | **Niobium (Nb)** | ~1.0 | Contributes to strengthening via γ' and γ'' phases. | | **Carbon (C)** | ~0.05 | Forms carbides for grain boundary strengthening. | | **Boron (B)** | ~0.005 | Strengthens grain boundaries. | | **Zirconium (Zr)** | ~0.05 | Enhances creep strength and grain boundary cohesion. | | **Iron (Fe)** | ≤ 1.0 | Residual element. | | **Manganese (Mn)** | ≤ 0.10 | Residual element. | | **Silicon (Si)** | ≤ 0.15 | Residual element. | | **Sulfur (S)** | ≤ 0.015 | Residual element. | #### **3. Physical Properties (Typical)** | Property | Value / Condition | | :--- | :--- | | **Density** | 8.10 g/cm³ (0.292 lb/in³) | | **Melting Range** | ~1330 - 1360 °C (~2425 - 2480 °F) | | **Thermal Expansion Coefficient** | ~13.5 μm/m·°C (20 - 100°C) | | **Thermal Conductivity** | ~11.5 W/m·K (at 100°C) | | **Electrical Resistivity** | ~1.25 μΩ·m | #### **4. Mechanical Properties** Mechanical properties are highly dependent on the heat treatment cycle. The following are typical minimum or average properties for bar stock after a standard solution and aging treatment (e.g., Solution Treat @ 1080°C, oil quench + Aging @ 845°C, air cool + Aging @ 760°C, air cool). **At Room Temperature:** * **Tensile Strength:** ≥ 1400 MPa (203 ksi) * **Yield Strength (0.2% Offset):** ≥ 1030 MPa (149 ksi) * **Elongation:** ≥ 12% * **Reduction of Area:** ≥ 15% **At Elevated Temperature (e.g., 730°C / 1350°F):** * **Tensile Strength:** ~1000 MPa (145 ksi) * **Yield Strength (0.2% Offset):** ~830 MPa (120 ksi) * **Creep Rupture Strength:** Excellent, capable of withstanding high stresses for extended periods (e.g., 100 hours rupture life > 400 MPa at 730°C). #### **5. Heat Treatment** UDIMET 520 requires a multi-step heat treatment to achieve its optimal properties: 1. **Solution Treatment:** Heated to a temperature above the γ' solvus (typically 1080°C / 1975°F) to dissolve the strengthening phases into the matrix, then rapidly cooled (quenched). 2. **Aging Treatment:** A two-stage aging process (e.g., 845°C / 1550°F and 760°C / 1400°F) is used to precipitate a fine, uniform distribution of the γ' phase throughout the matrix, providing maximum strength. #### **6. Product Applications** UDIMET 520 is used in the most demanding rotating and static components in high-pressure turbine sections, including: * **Turbine Blades and Buckets** * **Turbine Disks (Discs)** * **Compressor Disks (later stages)** * **Shafts** * **Spacers** * **High-Strength Fasteners** #### **7. International and Industry Standards** While UDIMET 520 is often procured to proprietary OEM specifications (like PDS 15125A1), it is also covered by several international standards. * **AMS:** **AMS 5704G** (Bars, forgings, and rings, 19Cr - 12.5Co - 6.2Mo - 3.0Ti - 1.0Nb, solution and precipitation heat treated) * **UNS:** **N07520** * **Werkstoff Nr.:** 2.4652 (Note: Always verify exact equivalence as compositions can have minor variations). * **Proprietary Specs:** PDS 15125A1, GE S-500, P&W CS-2100 (or similar, depending on the OEM). --- **Disclaimer:** The information provided herein is for reference purposes only. Properties can vary based on manufacturing process, heat treatment, and product form. For critical applications, the specific OEM or manufacturer's technical data sheets and specifications (like PDS 15125A1) must be consulted and followed. UDIMET is a registered trademark of Special Metals Corporation (a PCC company).

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 3359 gallon liquid totes Special package is available on request.