NIMONIC Alloy 81,Nickel-Chromium Alloy，1

### **Product Introduction: NIMONIC® Alloy 81** **NIMONIC® Alloy 81** is a nickel-chromium alloy that is precipitation-hardenable, designed to offer an excellent combination of high-temperature strength, oxidation resistance, and fabricability. It was developed to provide improved strength over solid-solution alloys like Nimonic 75 while maintaining good structural stability and corrosion resistance at elevated temperatures. This alloy is particularly noted for its good creep and rupture properties, making it suitable for moderately high-stress applications in aerospace and industrial engineering. Its balanced composition allows for effective strengthening through heat treatment while retaining good ductility and weldability. --- ### **Chemical Composition** The composition of Nimonic 81 is carefully balanced to provide optimal precipitation hardening response and environmental resistance. | Element | Content (%) | | :--- | :--- | | **Nickel (Ni)** | Balance | | **Chromium (Cr)** | 29.0 - 33.0 | | **Titanium (Ti)** | 1.8 - 2.7 | | **Aluminum (Al)** | 1.0 - 1.8 | | **Iron (Fe)** | 3.0 max | | **Cobalt (Co)** | 2.0 max | | **Carbon (C)** | 0.10 max | | **Silicon (Si)** | 1.0 max | | **Manganese (Mn)** | 1.0 max | | **Copper (Cu)** | 0.2 max | --- ### **Physical Properties** Nimonic 81 exhibits physical properties characteristic of nickel-chromium superalloys, suitable for high-temperature applications. | Property | Value | | :--- | :--- | | **Density** | 8.15 g/cm³ | | **Melting Point** | 1360-1410 °C | | **Thermal Conductivity** | 12.1 W/m·K (at 20°C) | | **Electrical Resistivity** | 1.20 μΩ·m | | **Modulus of Elasticity** | 220 GPa | | **Coefficient of Thermal Expansion** | 13.5 μm/m·°C (20-100°C) | | **Magnetic Response** | Essentially non-magnetic | --- ### **Mechanical Properties** The alloy develops its optimal mechanical properties through solution treatment and aging. **Typical Mechanical Properties (Solution Treated and Aged):** - **Tensile Strength:** 950-1150 MPa - **Yield Strength (0.2% Offset):** 650-800 MPa - **Elongation:** 20-30% - **Hardness:** 30-38 HRC --- ### **Key Characteristics & Advantages** 1. **Good High-Temperature Strength** - Maintains excellent mechanical properties at temperatures up to 850°C - Good creep and rupture strength 2. **Excellent Oxidation Resistance** - High chromium content provides superior resistance to oxidation and scaling - Performs well in corrosive atmospheres 3. **Good Fabricability** - Can be hot and cold worked using conventional methods - Good machinability in solution treated condition 4. **Weldability** - Can be welded using most standard techniques - Requires post-weld heat treatment for optimal properties --- ### **Product Applications** NIMONIC Alloy 81 finds application in various high-temperature sectors: **Aerospace Industry:** - Turbine blades and disks - Combustion chamber components - Afterburner parts - Exhaust system components **Industrial Applications:** - Gas turbine components - Heat treatment fixtures - Nuclear engineering components - High-temperature fasteners and bolts --- ### **International Standards** NIMONIC Alloy 81 is covered by several international specifications: | Standard Type | Standard Number | Description | | :--- | :--- | :--- | | **ISO** | 9725 | Nickel-chromium alloys | | **AMS** | 5876 | Aerospace Material Specification | | **BS** | HR 505 | British Standard | | **DIN** | 17742 | German Standard | | **Werkstoff** | 2.4632 | Material Number | --- ### **Summary** **NIMONIC Alloy 81** represents a well-balanced precipitation-hardenable nickel-chromium superalloy that offers an excellent combination of high-temperature strength, oxidation resistance, and fabricability. Its ability to maintain mechanical properties at elevated temperatures while providing good corrosion resistance makes it particularly valuable for critical components in aerospace and power generation industries. The alloy's versatility in manufacturing processes, combined with its reliable performance under demanding service conditions, ensures its continued use in applications where material failure is not an option. Its compliance with major international standards further enhances its global acceptance and utilization across various high-temperature engineering sectors.

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 3311 gallon liquid totes Special package is available on request.