Alloy 90,Nimonic 90,UNS N07090,E FORU

### **Alloy 90 / Nimonic® 90 / UNS N07090** **Precipitation-Hardenable Nickel-Chromium-Cobalt Superalloy for High-Temperature Applications** #### **1. Overview** **Alloy 90**, commercially known as **Nimonic® 90**, is a precipitation-hardenable nickel-chromium-cobalt superalloy that offers an excellent combination of high-temperature strength, corrosion resistance, and thermal stability. Developed for gas turbine applications, this alloy maintains its mechanical properties at temperatures up to 920°C (1688°F) through γ' (gamma prime) precipitation hardening. Nimonic 90 represents a significant advancement in superalloy technology, providing improved creep and fatigue resistance compared to earlier alloys while maintaining good fabricability. #### **2. Chemical Composition (Weight %)** The typical chemical composition of Nimonic 90 is outlined below. The balance is Nickel (Ni). | Element | Content (%) | Key Function | | :--- | :--- | :--- | | **Nickel (Ni)** | Balance | Forms the austenitic matrix and provides fundamental high-temperature strength. | | **Chromium (Cr)** | 18.0 - 21.0 | Provides oxidation and corrosion resistance at elevated temperatures. | | **Cobalt (Co)** | 15.0 - 21.0 | Enhances solid-solution strengthening and raises solvus temperature of γ' phase. | | **Titanium (Ti)** | 2.0 - 3.0 | Primary precipitation hardening element forming γ' phase (Ni₃Ti). | | **Aluminum (Al)** | 1.0 - 2.0 | Co-precipitates with titanium to form γ' phase (Ni₃(Al,Ti)). | | **Iron (Fe)** | 3.0 max | Controlled impurity; kept low to maintain high-temperature properties. | | **Manganese (Mn)** | 1.0 max | Improves hot workability. | | **Silicon (Si)** | 1.0 max | Enhances oxidation resistance. | | **Copper (Cu)** | 0.2 max | Controlled impurity. | | **Carbon (C)** | 0.08 - 0.16 | Forms carbides for grain boundary strengthening. | | **Boron (B)** | 0.003 - 0.010 | Enhances creep strength and grain boundary cohesion. | | **Zirconium (Zr)** | 0.02 - 0.12 | Improves creep-rupture properties. | | **Sulfur (S)** | 0.015 max | Impurity, kept low to prevent hot shortness. | #### **3. Physical Properties** | Property | Value / Condition | | :--- | :--- | | **Density** | 8.19 g/cm³ (0.296 lb/in³) | | **Melting Range** | ~ 1360 - 1410 °C (2480 - 2570 °F) | | **Mean Coefficient of Thermal Expansion** | 20 - 500°C (68 - 932°F): **13.8 x 10⁻⁶/°C** (7.7 x 10⁻⁶/°F)
20 - 800°C (68 - 1472°F): **14.9 x 10⁻⁶/°C** (8.3 x 10⁻⁶/°F) | | **Thermal Conductivity** | 16.5 W/m·K (114 Btu·in/hr·ft²·°F) at 20°C (68°F)
24.8 W/m·K (172 Btu·in/hr·ft²·°F) at 800°C (1472°F) | | **Specific Heat** | 450 J/kg·K (0.107 Btu/lb·°F) at 20°C (68°F) | | **Electrical Resistivity** | 1.26 μΩ·m at 20°C (68°F) | | **Modulus of Elasticity (Young's Modulus)** | 222 GPa (32.2 x 10⁶ psi) at 20°C (68°F) | | **Magnetic Permeability** | Essentially non-magnetic. | #### **4. Mechanical Properties (Typical for Aged Condition)** | Property | At Room Temperature | At 750°C (1382°F) | At 850°C (1562°F) | | :--- | :--- | :--- | :--- | | **Tensile Strength** | 1100 - 1300 MPa (160 - 188 ksi) | ~650 MPa (94 ksi) | ~450 MPa (65 ksi) | | **Yield Strength (0.2% Offset)** | 750 - 900 MPa (109 - 131 ksi) | ~550 MPa (80 ksi) | ~380 MPa (55 ksi) | | **Elongation (in 50 mm / 2 in)** | 15% - 25% | 15% - 30% | 20% - 35% | | **Hardness (Rockwell C)** | 30 - 38 HRC | - | - | #### **5. International Standards** Nimonic 90 is covered by several international and industry-specific standards: * **ASTM:** * **B 637:** Standard Specification for Precipitation-Hardening Nickel Alloy Bars, Forgings, and Forging Stock for High-Temperature Service * **AMS:** * **AMS 5547:** Sheet, Strip, and Plate * **AMS 5699:** Wire for Springs * **AMS 5705:** Bar and Forging Stock * **BS / EN:** * **BS HR 505:** Aerospace series * **EN 10095:** Heat resisting steels and nickel alloys * **UNS:** N07090 * **DIN:** 2.4969 (Material Number) * **ISO:** ISO 9723, ISO 9724 * **AECMA:** PR EN 2951 #### **6. Product Applications** Nimonic 90 is extensively used in high-temperature applications requiring excellent creep and fatigue resistance: * **Aerospace & Gas Turbines:** * Turbine blades and vanes * Discs and shafts * Combustion chamber components * Afterburner parts * **Industrial Gas Turbines:** * Rotor blades * Stator vanes * High-temperature fasteners * **Automotive Turbochargers:** * Turbine wheels * Shafts and rotors * **Nuclear Industry:** * Core components * Heat exchanger parts * **General Engineering:** * High-temperature springs * Fasteners for elevated temperature service * Hot work tooling #### **7. Key Characteristics & Advantages** * **Excellent Creep Resistance:** Outstanding performance under sustained loading at temperatures up to 920°C (1688°F) * **High-Temperature Strength:** Superior mechanical properties maintained at elevated temperatures through γ' precipitation hardening * **Good Oxidation Resistance:** Resists scaling and oxidation in high-temperature environments * **Excellent Fatigue Resistance:** Withstands cyclic loading conditions at high temperatures * **Thermal Stability:** Maintains microstructural integrity during long-term exposure * **Good Fabricability:** Can be forged, formed, and welded using appropriate techniques * **Optimized Balance:** Provides an excellent balance between strength, ductility, and environmental resistance --- **Disclaimer:** *Nimonic® is a registered trademark of Rolls-Royce plc. 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 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 1658 gallon liquid totes Special package is available on request.