Nilo 45 (also known as 4J45, Fe-Ni45, UNS K94610, German Standard W. Nr 1.3918, ASTM B637) is a high-performance iron-nickel based constant expansion precision alloy, belonging to the derivative model of Invar alloy series. As a core sealing material in the electro-vacuum industry, Nilo 45 has a stable low coefficient of thermal expansion in the wide temperature range of -70℃~500℃, which is highly matched with the expansion coefficient of hard glass, alumina ceramics and other materials. It is widely used in high-end fields such as electronic packaging, precision instruments, aerospace, and is the preferred material that balances dimensional stability and processing performance.
Nilo 45 (UNS K94610) Chemical Composition (ASTM B637/GB/T 15018 Standard)
The detailed chemical composition table is as follows:
Element | Content Range (%) |
Ni | 44.5~45.5 |
Fe | Balance |
C | ≤0.05 |
Si | ≤0.30 |
Mn | ≤0.60 |
P | ≤0.020 |
S | ≤0.020 |
Nilo 45 (UNS K94610) Core Performance Parameters
The core advantage of Nilo 45 is its stable low thermal expansion characteristics, along with good mechanical properties and corrosion resistance. The detailed parameters are as follows (room temperature standard, custom special needs available):
1. Physical Properties
Performance Indicator | Parameter Value | Practical Description |
Density | 8.2 g/cm³ | Standard value at 20℃, suitable for precision structural design |
Coefficient of Thermal Expansion (20~500℃) | (4.5~5.2)×10⁻⁶/℃ | Highly matched with hard glass and ceramics, no stress during sealing |
Curie Temperature | Approx. 400℃ | Higher than Nilo 42, wider applicable temperature range |
Resistivity | Approx. 0.48 μΩ·m | Standard value at 20℃, suitable for conductive needs of electronic devices |
Thermal Conductivity | 16.5 W/(m·K) | At 20℃, ensuring uniform heat conduction |
Specific Heat Capacity | 502 J/(kg·K) | At 20℃, stable performance when temperature changes |
Melting Point | 1450~1500℃ | Suitable for high-temperature processing and sealing processes |
2. Mechanical Properties
Performance Indicator | Typical Value | Application Reference |
Tensile Strength | ≥490 MPa | Meet the strength requirements of structural parts |
Yield Strength | ≥210 MPa | Ensure dimensional stability after processing |
Elongation | ≥30% | Facilitate complex processing such as cold rolling and deep drawing |
Hardness (HB) | ≤195 | Easy to cut and form |
Elastic Modulus | 160 GPa | Suitable for precision instrument structural design |
3. Nilo 45 (UNS K94610) Core Features
Constant Expansion High Matching: The coefficient of thermal expansion is almost constant in the temperature range of 20~400℃. The interface stress is extremely small when sealing with hard glass and ceramics, ensuring air tightness and long-term structural stability, and solving the problem of sealing cracking.
Stable Organizational Structure: Single-phase austenitic structure, no magnetic transformation, performance is not easy to decay after hot and cold processing, and dimensional accuracy is controllable.
Excellent Corrosion Resistance: It performs well in the atmosphere, fresh water and mild corrosive media, suitable for harsh environments such as electronic packaging and medical equipment.
Excellent Processing Performance: Easy to hot and cold process, weld and cut, can be made into various forms to meet the customization needs of different scenarios.
Nilo 45 (UNS K94610) Processing and Heat Treatment Technology
Nilo 45 has good adaptability to processing and heat treatment. Reasonable technology can further improve material performance and adapt to various complex application scenarios:
1. Processing Performance
Hot and Cold Processing: Due to the characteristics of austenitic structure, it can be easily cold-rolled, hot-rolled and forged, and can be made into various forms such as thin plates, strips, wires, bars and pipes.
Welding Performance: Supports arc welding, resistance welding and brazing. The weld performance is consistent with the matrix without obvious performance attenuation, suitable for the manufacture of sealed structures.
Machining Performance: Similar to austenitic stainless steel, it can be cut at low speed with carbide tools, with high processing efficiency and controllable surface accuracy.
Deep Drawing Performance: After soft annealing, it has excellent deep drawing and stretching performance, which can be used to manufacture complex-shaped electronic component frames and seals.
2. Heat Treatment Process
Soft Annealing: Hold at 850~900℃ for 1~2 hours, air cool or furnace cool, mainly used to improve processing performance and facilitate subsequent forming.
Aging Treatment: Aging at 300~500℃ as needed can effectively stabilize the material size and avoid deformation during use.
Pre-sealing Treatment: Bright annealing or pickling is required to ensure the surface is clean and free of impurities, improving sealing quality and air tightness.
Nilo 45 (UNS K94610) Main Application Fields
With stable constant expansion characteristics and good comprehensive performance, Nilo 45 is widely used in high-end fields such as electronics, precision instruments, aerospace. The specific scenarios are as follows:
1. Electronic Packaging and Electro-Vacuum Devices
As a core material for hard glass/ceramic sealing, Nilo 45 can be used for leads, frames and sealed plugs of electron tubes, transistors and integrated circuits; semiconductor lead frames (especially devices requiring sealing with hard glass/ceramic); sealed components of vacuum switches and relays, ensuring air tightness and long-term stability of devices.
2. Precision Instruments and Measuring Equipment
Suitable for thermostats, thermal bimetallic strips and temperature controller components; skeleton materials of precision resistors and potentiometers; structural parts of high-precision measuring instruments, which can effectively avoid dimensional deformation caused by temperature changes and ensure measurement accuracy.
3. Aerospace and Composite Materials
Used for aerospace composite material forming tooling and molds to ensure the dimensional accuracy of parts; precision structural parts in satellites and spacecraft, which can adapt to wide temperature range changes in space; optical instrument components to avoid temperature deformation affecting optical performance.
4. Other Special Applications
Precision components in medical equipment (such as sensor housings); sealing and connecting components in automotive electronics; structural components in microwave devices and communication equipment, adapting to the needs of various harsh environments.
Nilo 45 (UNS K94610) Alloy Summary
Nilo 45 (UNS K94610, 4J45, Fe-Ni45) is a high-performance constant expansion precision alloy. With its stable low coefficient of thermal expansion in the wide temperature range of -70℃~500℃, high matching with hard glass/ceramics, and good processing and corrosion resistance, it has become an indispensable key material in fields such as electronic packaging, precision instruments and aerospace. We provide standardized products and customized services, strictly control product quality, and ensure that each batch of Nilo 45 products meets ASTM B637 and GB/T 15018 standards to meet your various application needs.
If you need samples, quotes or customized solutions for Nilo 45 (UNS K94610) alloy, please feel free to contact us, and we will provide you with professional technical support and efficient delivery services.
