NILO Alloy 48 Controlled-Expansion Alloy,UNS K94800; 1

### **Product Introduction: NILO® Alloy 48 (UNS K94800)** **NILO® Alloy 48** is a nickel-iron controlled-expansion alloy specifically engineered to exhibit a low and predictable thermal expansion coefficient that closely matches that of hard glass and alumina ceramics. This specialized alloy is part of the NILO (Nickel-Low Expansion) series, designed for applications requiring precise dimensional stability and thermal matching between metal and ceramic or glass components over a specific temperature range. The alloy's unique thermal expansion characteristics make it particularly valuable for electronic packaging, semiconductor applications, and precision instruments where reliable performance under thermal cycling is essential. --- ### **Chemical Composition** | Element | Content (%) | |---------|-------------| | **Nickel (Ni)** | 47.5 - 48.5 | | **Iron (Fe)** | Balance | | **Manganese (Mn)** | 0.30 - 0.60 | | **Silicon (Si)** | 0.15 - 0.30 | | **Carbon (C)** | 0.05 max | | **Copper (Cu)** | 0.10 max | | **Chromium (Cr)** | 0.10 max | | **Aluminum (Al)** | 0.10 max | | **Sulfur (S)** | 0.015 max | | **Phosphorus (P)** | 0.015 max | --- ### **Physical Properties** | Property | Value | |----------|-------| | **Density** | 8.22 g/cm³ | | **Melting Point** | 1427 °C | | **Thermal Conductivity** | 14.0 W/m·K (at 20°C) | | **Electrical Resistivity** | 0.45 μΩ·m | | **Modulus of Elasticity** | 148 GPa | | **Mean Coefficient of Thermal Expansion** | 8.5 - 9.5 × 10⁻⁶/°C (20-300°C) | | **Specific Heat Capacity** | 500 J/kg·K | | **Curie Temperature** | 360 - 380 °C | --- ### **Mechanical Properties** **Annealed Condition:** - **Tensile Strength:** 510 - 620 MPa - **Yield Strength (0.2% Offset):** 280 - 380 MPa - **Elongation:** 30 - 40% - **Hardness:** 70 - 85 HRB **Cold Worked Condition:** - **Tensile Strength:** 620 - 830 MPa - **Yield Strength (0.2% Offset):** 480 - 690 MPa - **Elongation:** 10 - 25% - **Hardness:** 85 - 100 HRB --- ### **Heat Treatment** **Stress Relieving:** - **Temperature:** 425 - 540°C (800 - 1000°F) - **Time:** 1-2 hours - **Atmosphere:** Hydrogen or vacuum recommended **Annealing:** - **Temperature:** 760 - 870°C (1400 - 1600°F) - **Cooling:** Controlled cooling rate essential --- ### **Key Characteristics & Advantages** 1. **Controlled Thermal Expansion** - Low thermal expansion coefficient matching hard glass and ceramics - Predictable expansion behavior over temperature ranges - Excellent dimensional stability 2. **Excellent Sealing Characteristics** - Compatible with various glass and ceramic materials - Reliable performance in hermetic sealing applications - Good wetting and bonding properties 3. **Good Mechanical Properties** - Adequate strength for structural applications - Good formability and machinability - Suitable for precision manufacturing 4. **Stable Performance** - Consistent properties over thermal cycles - Resistance to thermal fatigue - Long-term reliability in sealed applications --- ### **Product Applications** **Electronics and Semiconductor:** - IC packages and lead frames - Microwave and RF packages - Power semiconductor packages - Hybrid circuit substrates **Aerospace and Defense:** - Avionics packaging - Radar system components - Military electronic systems - Spacecraft instrumentation **Industrial Applications:** - Glass-to-metal seals - Ceramic-to-metal seals - Precision instruments - Optical components **Specialized Applications:** - Laser diode packages - Fiber optic components - Sensor housings - Vacuum tube components --- ### **International Standards** | Standard Type | Standard Number | Description | |---------------|-----------------|-------------| | **UNS** | K94800 | Unified Numbering System | | **ASTM** | F30 | Alloys for Glass-to-Metal Seals | | **DIN** | 17745 | German Standard | | **Werkstoff Nr.** | 1.3922, 1.3926, 1.3927 | Material Numbers | | **AFNOR** | NF A54-301 | French Standard | --- ### **Summary** **NILO® Alloy 48 (UNS K94800)** is a precision nickel-iron controlled-expansion alloy specifically formulated to provide thermal expansion characteristics that closely match hard glass and alumina ceramics. Its predictable and stable thermal behavior makes it an essential material for electronic packaging, semiconductor applications, and precision sealing components where reliable performance under thermal cycling is critical. The alloy's excellent sealing compatibility, combined with good mechanical properties and manufacturing characteristics, ensures reliable performance in demanding applications ranging from consumer electronics to aerospace systems. Comprehensive certification to international standards including ASTM F30, DIN 17745, and AFNOR NF A54-301 guarantees consistent quality and performance, providing engineers with a trusted solution for applications requiring precise thermal matching and dimensional stability in critical electronic and optical systems.

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 3343 gallon liquid totes Special package is available on request.