Alloy 25 / L605,Udimet L605,UNS W73605,E FORU

### **Alloy 25 / L605 / Udimet® L605 / UNS W73605** **Cobalt-Chromium-Tungsten-Nickel Superalloy for Extreme Service Conditions** 

 --- #### **1. Overview** 

 **Alloy 25**, commercially known as **Udimet® L605**, is a cobalt-based superalloy renowned for its exceptional high-temperature strength, outstanding oxidation resistance, and excellent wear characteristics. This solid-solution strengthened alloy maintains remarkable mechanical properties at temperatures up to 980°C (1800°F) and exhibits good thermal fatigue resistance. Originally developed for aerospace applications, Udimet L605 has proven invaluable in the most demanding environments where both mechanical integrity and corrosion resistance are critical. 

 --- #### **2. Chemical Composition (Weight %)

** The typical chemical composition of Udimet L605 is outlined below. The balance is Cobalt (Co). 

| Element | Content (%) | Key Function | 

| :--- | :--- | :--- | 

| **Cobalt (Co)** | Balance | Forms the primary matrix with exceptional high-temperature stability and strength retention. | 

| **Chromium (Cr)** | 19.0 - 21.0 | Provides superior oxidation and hot corrosion resistance through protective oxide layer formation. | 

| **Tungsten (W)** | 14.0 - 16.0 | Primary solid-solution strengthener; significantly enhances high-temperature strength and wear resistance. | 

| **Nickel (Ni)** | 9.0 - 11.0 | Stabilizes the austenitic structure and improves workability and ductility. | 

| **Iron (Fe)** | 2.0 max | Controlled impurity to maintain corrosion resistance. | 

| **Manganese (Mn)** | 1.0 - 2.0 | Enhances hot workability and acts as a deoxidizer during melting. | 

| **Silicon (Si)** | 0.30 - 0.60 | Improves oxidation resistance and fluidity during casting. | 

| **Carbon (C)** | 0.07 - 0.15 | Forms carbides for secondary strengthening and enhanced wear resistance. | 

| **Boron (B)** | 0.005 - 0.015 | Improves creep strength and grain boundary cohesion. | 

| **Phosphorus (P)** | 0.02 max | Controlled impurity. | 

| **Sulfur (S)** | 0.02 max | Controlled impurity to prevent hot shortness. | 

 --- #### **3. Physical Properties**

| Property | Value / Condition | 

| :--- | :--- | 

| **Density** | 9.15 g/cm³ (0.331 lb/in³) | 

| **Melting Range** | ~ 1345 - 1425 °C (2450 - 2600 °F) | 

| **Mean Coefficient of Thermal Expansion** | 20 - 540°C (68 - 1000°F): **14.2 x 10⁻⁶/°C** (7.9 x 10⁻⁶/°F)
20 - 980°C (68 - 1800°F): **15.8 x 10⁻⁶/°C** (8.8 x 10⁻⁶/°F) | 

| **Thermal Conductivity** | 9.8 W/m·K (68 Btu·in/hr·ft²·°F) at 21°C (70°F)
22.5 W/m·K (156 Btu·in/hr·ft²·°F) at 540°C (1000°F) | 

| **Specific Heat** | 425 J/kg·K (0.102 Btu/lb·°F) at 21°C (70°F) | 

| **Electrical Resistivity** | 0.94 μΩ·m at 21°C (70°F) | 

| **Modulus of Elasticity (Young's Modulus)** | 245 GPa (35.5 x 10⁶ psi) at 21°C (70°F) | 

| **Magnetic Permeability** | Essentially non-magnetic in all conditions. | 

 --- #### **4. Mechanical Properties 

(Typical for Annealed Condition)** 

| Property | At Room Temperature | At 815°C (1500°F) | At 980°C (1800°F) | 

| :--- | :--- | :--- | :--- | 

| **Tensile Strength** | 980 - 1250 MPa (142 - 181 ksi) | ~280 MPa (41 ksi) | ~150 MPa (22 ksi) | 

| **Yield Strength (0.2% Offset)** | 480 - 720 MPa (70 - 104 ksi) | ~190 MPa (28 ksi) | ~110 MPa (16 ksi) | 

| **Elongation (in 50 mm / 2 in)** | 35% - 55% | 45% - 65% | 60% - 80% | 

| **Hardness (Rockwell B)** | 92 - 102 HRB | - | - | 

 --- #### **5. International Standards** 

 Udimet L605 conforms to the following international specifications: 

 *   **ASTM:**    

*   **B811:** Standard Specification for Wrought Cobalt-20Chromium-15Tungsten-10Nickel Alloy for Aerospace Application    

*   **F90:** Standard Specification for Wrought Cobalt-20Chromium-15Tungsten-10Nickel Alloy for Surgical Implant Applications 

*   **AMS:**   

 *   **AMS 5537:** Sheet, Strip, and Plate    

*   **AMS 5759:** Bar and Forging Stock    

*   **AMS 5796:** Welding Wire 

*   **ISO:**    

*   **ISO 5832-6:** Implants for surgery — Metallic materials — Part 6: Wrought cobalt-nickel-chromium-molybdenum alloy 

*   **UNS:** W73605 

*   **EN (European Standard):

** 2.4964 *   **AECMA:** PR EN 3957 

 --- #### **6. Product Applications** 

 Udimet L605 serves critical functions across multiple high-performance industries: 

 *   **Aerospace & Defense:

**    *   Turbine blades and vanes    

*   Combustion chambers and afterburner components    

*   Exhaust systems and thrust reversers    

*   Rocket motor components 

*   **Medical Technology:

**    *   Orthopedic implants requiring high wear resistance    

*   Surgical instruments    

*   Dental prosthetics 

*   **Industrial Equipment:

**    *   Heat treatment fixtures and furnace components    

*   High-temperature valves and pumps    

*   Wear plates and cutting tools 

*   **Power Generation:

**    *   Gas turbine components    

*   High-temperature fasteners and hardware

 --- #### **7. Key Characteristics & Advantages*

* *   **Exceptional High-Temperature Capability:

** Maintains mechanical properties up to 980°C (1800°F) 

*   **Superior Oxidation Resistance:

** Excellent performance in oxidizing atmospheres up to 1095°C (2000°F) 

*   **Outstanding Wear and Galling Resistance:

** Ideal for applications involving friction and mechanical wear 

*   **Good Thermal Fatigue Resistance:** Withstands repeated thermal cycling without degradation 

*   **Excellent Fabricability:** Can be welded, formed, and machined using appropriate techniques 

*   **Biocompatibility:** Certified for medical implant applications 

*   **Non-Magnetic Properties:

** Suitable for sensitive electronic and measurement applications

 --- **Disclaimer:

** *Udimet® is a registered trademark of Special Metals Corporation. The values provided are typical and for informational purposes only. For critical applications, always consult the official material data sheets from the supplier and relevant design codes.*

Packing of Alloy 25 / L605,Udimet L605,UNS W73605

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 1667 gallon liquid totes Special package is available on request.