4J45 is a nickel-iron controlled expansion alloy that has become a preferred material for precision electronic and semiconductor packaging applications. It offers exceptional dimensional stability, thermal compatibility with ceramic and glass materials, and superior bonding performance. At DLX Alloy, we specialize in manufacturing high-purity 4J45 wire optimized for semiconductor encapsulation, ensuring reliability and precision for high-end electronic systems.
For more details, pls directly contact us.
4J45 is composed of approximately 45% nickel and 55% iron, designed to maintain a low and stable coefficient of thermal expansion (CTE). Its expansion rate matches that of certain glasses and ceramics, making it ideal for sealing and packaging applications where different materials are joined together.
The alloy’s stability across a wide temperature range helps prevent mechanical stress, cracking, or leakage—critical issues in semiconductor and vacuum device manufacturing. DLX Alloy’s proprietary melting and refining techniques ensure uniform microstructure, minimal impurities, and precise expansion control.
Key Features:
-
Controlled coefficient of thermal expansion (5.3–5.5×10⁻⁶/°C)
-
Excellent machinability and ductility
-
Good magnetic and mechanical stability
-
High bond strength with glass and ceramic materials
-
Consistent performance in vacuum and inert atmospheres
Alloy Composition Table
|
Alloy Grades |
C |
S |
P |
Mn |
Si |
Ni |
Cr |
Co |
Mo |
Cu |
Al |
Nb |
Fe |
Other Elements |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
1J06 |
0.04 |
0.015 |
0.015 |
≤0.10 |
≤0.15 |
- |
- |
- |
- |
- |
5.5-6.5 |
- |
Rest |
- |
|
1J12 |
0.03 |
0.015 |
0.015 |
≤0.10 |
≤0.15 |
- |
- |
- |
- |
- |
11.6-12.4 |
- |
Rest |
- |
|
1J17 |
0.03 |
0.02 |
0.02 |
≤0.60 |
≤0.20 |
- |
15.5-16.5 |
- |
- |
- |
- |
- |
Rest |
- |
|
1J18 |
0.03 |
0.02 |
0.02 |
0.3-0.7 |
≤0.15 |
0.5-0.7 |
17-18.5 |
- |
- |
- |
- |
- |
Rest |
Ti: 0.3-0.7 |
|
0.04 |
0.02 |
0.02 |
≤0.3 |
≤0.3 |
≤0.5 |
- |
49-51 |
- |
≤0.2 |
- |
- |
Rest |
V: 0.8-1.8 |
|
|
1J30 |
0.04 |
0.02 |
0.02 |
≤0.40 |
≤0.30 |
29.5-30.5 |
- |
- |
- |
- |
- |
- |
Rest |
- |
|
1J36 |
0.03 |
0.02 |
0.02 |
≤0.60 |
≤0.20 |
35.0-37.0 |
- |
- |
- |
- |
- |
- |
Rest |
- |
|
1J38 |
0.03 |
0.05 |
0.02 |
0.3-0.6 |
0.15-0.3 |
37.5-38.5 |
12.5-13.5 |
- |
- |
- |
- |
- |
Rest |
- |
|
1J46 |
0.03 |
0.02 |
0.02 |
0.6-1.1 |
0.15-0.3 |
45.0-46.5 |
- |
- |
- |
≤0.2 |
- |
- |
Rest |
- |
|
0.03 |
0.02 |
0.02 |
0.3-0.6 |
0.15-0.3 |
49-50.5 |
- |
- |
- |
≤0.2 |
- |
- |
Rest |
- |
|
|
1J51 |
0.03 |
0.02 |
0.02 |
0.3-0.6 |
0.15-0.3 |
49-50.5 |
- |
- |
- |
≤0.2 |
- |
- |
Rest |
- |
|
1J54 |
0.03 |
0.02 |
0.02 |
0.3-0.6 |
1.1-1.4 |
49.5-51 |
3.8-4.2 |
- |
- |
≤0.2 |
- |
- |
Rest |
- |
|
1J76 |
0.03 |
0.02 |
0.02 |
0.3-0.6 |
0.15-0.3 |
75.0-76.5 |
1.8-2.2 |
- |
- |
4.8-5.2 |
- |
- |
Rest |
- |
|
1J77 |
0.03 |
0.02 |
0.02 |
0.3-0.6 |
0.15-0.3 |
75.5-78 |
- |
- |
3.9-4.5 |
4.8-6.0 |
- |
- |
Rest |
- |
|
1J79 |
0.03 |
0.02 |
0.02 |
0.6-1.10 |
0.3-0.5 |
78.5-80.0 |
- |
- |
3.8-4.1 |
≤0.2 |
- |
- |
Rest |
- |
|
1J80 |
0.03 |
0.02 |
0.02 |
0.6-1.10 |
1.1-1.5 |
79.0-81.5 |
2.6-3.0 |
- |
- |
≤0.2 |
- |
- |
Rest |
- |
|
0.03 |
0.02 |
0.02 |
0.3-0.60 |
0.15-0.3 |
79.0-81.0 |
- |
- |
4.8-5.2 |
≤0.2 |
- |
- |
Rest |
- |
|
|
1J87 |
0.03 |
0.02 |
0.02 |
0.3-0.6 |
≤0.3 |
78.5-80.5 |
- |
- |
1.6-2.2 |
- |
- |
6.5-7.5 |
Rest |
- |
For more details, pls directly contact us.
The controlled expansion and mechanical properties of 4J45 make it a go-to material for a range of advanced applications:
-
Semiconductor Packaging: Used as a lead frame or structural component to minimize thermal mismatch during device operation.
-
Hermetic Sealing Systems: Maintains tight seals with glass or ceramic materials in high-reliability microelectronic packages.
-
Precision Instruments: Ideal for components requiring stable mechanical dimensions under thermal cycling.
-
Sensor Housings: Ensures consistent performance in environmental and magnetic sensors.
-
Optoelectronic Devices: Provides stable mechanical interfaces for fiber optic and laser assemblies.
-
Vacuum Devices: Serves as a sealing material in electronic tubes and transistors.
At DLX Alloy, our 4J45 wire is supplied in various tempers and surface finishes, from bright-annealed to oxide-coated, enabling customers to select the ideal specification for their sealing or packaging processes.
The global semiconductor industry is moving rapidly toward miniaturization, high-density integration, and thermal reliability. These changes have increased the need for materials with precise expansion control like 4J45. In high-end semiconductor and MEMS packaging, the mismatch between silicon chips and their metal frames can cause mechanical strain, leading to device failure.
As a result, controlled expansion alloys such as 4J45 are now being used more extensively for ceramic-to-metal seals, transistor headers, and lead frames in semiconductor devices. At DLX Alloy, we’re seeing growing demand from customers developing power semiconductors, automotive electronics, and aerospace-grade sensors, all of which depend on 4J45’s unmatched thermal stability.
| Property | 4J45 (Ni45Fe) | 4J42 (Ni42Fe) | Stainless Steel 304 |
|---|---|---|---|
| Nickel Content (%) | ~45 | ~42 | 8–10 |
| Coefficient of Expansion (×10⁻⁶/°C) | 5.3–5.5 | 5.0–5.3 | 17.3 |
| Density (g/cm³) | 8.15 | 8.12 | 7.9 |
| Electrical Resistivity (μΩ·m) | 0.47 | 0.49 | 0.73 |
| Thermal Conductivity (W/m·K) | 15.5 | 14.8 | 16.3 |
| Melting Point (°C) | 1440 | 1450 | 1400 |
| Sealing Compatibility | Glass/Ceramic | Glass/Ceramic | Poor |
| Corrosion Resistance | Moderate | Moderate | Excellent |
4J45 provides slightly higher thermal expansion than 4J42, making it particularly compatible with certain ceramic materials used in semiconductor encapsulation. While stainless steel is cost-effective, it cannot provide the same expansion matching and sealing performance needed in precision semiconductor applications.
DLX Alloy Advantages
DLX Alloy has spent years refining its controlled expansion alloy production technology, ensuring that every meter of 4J45 wire meets the rigorous demands of semiconductor and electronics manufacturing. Our advantages lie in:
-
Precision Metallurgy:
Using vacuum induction melting and secondary refining, DLX Alloy achieves extremely uniform composition control, minimizing impurities that affect sealing behavior. -
Dimensional Accuracy:
We maintain tight tolerances on wire diameter and roundness through precision drawing and annealing, guaranteeing compatibility with automated assembly and bonding equipment. -
Excellent Surface Finish:
A smooth, oxide-free surface ensures strong bonding to glass or ceramic substrates and minimizes microcracks during sealing. -
Flexible Customization:
DLX Alloy provides tailored solutions—different diameters, tensile strengths, or surface treatments—based on customer sealing and welding needs. -
Comprehensive Quality Testing:
Each production batch undergoes expansion coefficient verification, microstructure analysis, and mechanical testing to guarantee consistent results. -
Global Delivery & Support:
With an optimized logistics network, DLX Alloy ensures timely delivery to global semiconductor and electronics manufacturers.
Our mission is not only to supply controlled expansion alloys but to enable our clients’ reliability and performance through material excellence.
Controlled expansion alloys like 4J45 are experiencing steady demand growth due to the continuous evolution of semiconductor, aerospace, and optoelectronic industries. The increasing emphasis on high-temperature stability and hermetic integrity in packaging materials is pushing manufacturers to adopt nickel-iron alloys for new-generation device platforms.
DLX Alloy continues to innovate by improving 4J45 wire consistency, mechanical strength, and bonding performance. We are also developing new forming and annealing processes to better meet the needs of automated microelectronic assembly lines.
With the global push for smaller, faster, and more reliable chips, 4J45 alloy will remain a key foundation in the semiconductor packaging value chain, and DLX Alloy will stay at the forefront of this transformation through continuous technical improvement and reliable material supply.
About Us:
Our 12,000㎡ factory is equipped with complete capabilities for research, production, testing, and packaging. We strictly adhere to ISO 9001 standards in our production processes, with an annual output of 1,200 tons. This ensures that we meet both quantity and quality demands. Furthermore, all products undergo rigorous simulated environment testing including high temperature, high pressure, and corrosion tests before being dispatched, ensuring they meet customer specifications.
For all our clients, we offer timely and multilingual after-sales support and technical consulting, helping you resolve any issues swiftly and efficiently.
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We support all kinds of testing:
1. What is 4J45 alloy mainly used for?
It’s primarily used in semiconductor packaging, glass-to-metal seals, and ceramic-to-metal joints due to its controlled thermal expansion.
2. Why is 4J45 preferred in microelectronics?
Its thermal expansion closely matches ceramics, preventing cracks and stress during temperature fluctuations.
3. What’s the difference between 4J45 and 4J42?
4J45 has a slightly higher nickel content and expansion rate, making it more suitable for specific glass and ceramic sealing applications.
4. Does DLX Alloy provide custom sizes?
Yes, we supply 4J45 wire in various diameters and mechanical conditions according to customer requirements.
5. How is 4J45 manufactured at DLX Alloy?
It’s produced through vacuum melting, precision rolling, and controlled annealing for consistent performance.
6. Can 4J45 wire be used for magnetic applications?
While it has magnetic properties, it’s primarily optimized for dimensional stability rather than magnetic permeability.
7. What surface finishes are available?
We offer bright, annealed, or oxide-coated finishes depending on the sealing process.
8. What industries commonly use 4J45 wire?
Semiconductors, electronics, aerospace, optics, and precision instrument manufacturing.
