The 4J43 alloy plate is a specialized material engineered for hermetic sealing and precision joining applications, where dimensional stability under temperature changes is critical. With its controlled thermal expansion, high mechanical stability, and excellent corrosion resistance, it is widely used in vacuum devices, electronic packaging, and aerospace systems. At DLX Alloy, we produce 4J43 plates with a strong focus on material reliability, consistency, and performance verification to ensure our clients achieve optimal results in critical applications.
4J43 is a nickel-iron-cobalt controlled Expansion Alloy designed to match the thermal expansion of ceramics, glass, and other hermetically sealed materials. Its key property is the ability to maintain dimensional integrity over a broad temperature range, minimizing thermal stress at interfaces. This makes it ideal for glass-to-metal seals, vacuum tubes, and high-precision electronic devices.
DLX Alloy manufactures 4J43 plates through vacuum induction melting, precision rolling, and stress-relief annealing. This process ensures uniform expansion properties, smooth surface finish, and high mechanical reliability. Each batch undergoes rigorous thermal expansion testing, dimensional control, and mechanical verification to guarantee it meets the exacting standards required in hermetic sealing applications.
|
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 |
- |
|
1J50 |
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.
-
Hermetic sealing of electronic devices: Ensures airtight assembly in semiconductors, vacuum tubes, and RF components.
-
Glass-to-metal seals: Matches thermal expansion with borosilicate and aluminosilicate glass for stress-free bonding.
-
Aerospace and defense: Used in vacuum sensors, avionics, and satellite components for dimensional stability under temperature fluctuation.
-
Medical devices: Critical for sterile and sealed devices such as vacuum pumps and diagnostic equipment.
-
Optoelectronics and laser systems: Provides stable mounting and alignment of sensitive optical components.
Material Composition
| Element | Content (%) |
|---|---|
| Nickel (Ni) | 42–44 |
| Iron (Fe) | Balance |
| Cobalt (Co) | 1.5–2.0 |
| Manganese (Mn) | ≤0.5 |
| Silicon (Si) | ≤0.3 |
| Carbon (C) | ≤0.03 |
| Sulfur (S) | ≤0.02 |
| Phosphorus (P) | ≤0.02 |
| Property | Unit | Typical Value |
|---|---|---|
| Density | g/cm³ | 8.2 |
| Thermal Expansion Coefficient (20–300°C) | 10⁻⁶/K | 5.0–6.0 |
| Curie Temperature | °C | ~420 |
| Yield Strength | MPa | 350–400 |
| Tensile Strength | MPa | 700–750 |
| Elongation | % | 15–18 |
| Hardness | HV | ≤180 |
| Electrical Resistivity | μΩ·cm | 50–60 |
The demand for controlled expansion alloys like 4J43 has been rising steadily due to the growth of vacuum electronics, high-reliability medical devices, and aerospace systems. Modern instrumentation increasingly requires materials that can maintain hermetic integrity under thermal cycling without introducing stress that could compromise device performance.
Industry research shows that global adoption of nickel-iron-cobalt alloys in vacuum sealing and precision electronics is expected to grow by 25–30% over the next five years, driven by miniaturization and high-reliability standards. Additionally, as devices operate under extreme conditions — including temperature swings, vibration, and pressure — materials like 4J43, with controlled expansion and superior mechanical properties, are becoming a preferred choice over traditional stainless steels or low-expansion alloys.
DLX Company Advantage
DLX Alloy has extensive experience in producing high-precision controlled expansion materials. Our expertise ensures 4J43 plates meet stringent performance requirements for hermetic sealing applications.
1. Precision Alloying: High-purity nickel, iron, and cobalt sources allow for precise control of thermal expansion coefficients.
2. Vacuum Melting and Stress Relief: Reduces internal impurities and residual stress, enhancing dimensional stability across the operating temperature range.
3. Surface Quality and Flatness: Optimized cold rolling and polishing techniques produce plates ideal for sealing interfaces with glass or ceramic.
4. Tailored Solutions: Thickness, dimensions, and expansion coefficients can be customized to match specific design requirements for hermetic applications.
5. Third-Party Verification: Independent labs validate expansion coefficients, mechanical properties, and metallurgical consistency to assure reliable performance.
6. Field-Tested Reliability: DLX’s 4J43 has been successfully used in aerospace sensors, medical diagnostic equipment, and high-precision optical assemblies, providing real-world validation of stability and performance.
| Property | DLX 4J43 Alloy Plate | Standard 4J42 | Low-Expansion Alloy (Kovar) |
|---|---|---|---|
| Nickel Content (%) | 42–44 | 42 | 29 |
| Cobalt Content (%) | 1.5–2.0 | 1.0 | 17 |
| Thermal Expansion (10⁻⁶/K) | 5.0–6.0 | 5.5–6.5 | 4.5–5.0 |
| Yield Strength (MPa) | 350–400 | 330–380 | 300–350 |
| Surface Finish | Excellent | Good | Moderate |
| Recommended Use | Hermetic sealing, precision devices | General low-expansion | Optical and vacuum applications |
Interpretation:
DLX 4J43 achieves tighter control of thermal expansion and higher mechanical stability than 4J42, providing better sealing integrity under thermal cycling. Compared to standard Kovar, 4J43 offers improved machinability and surface quality while maintaining precise expansion matching.
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:
FAQs:
1. What makes 4J43 suitable for hermetic sealing?
Its controlled thermal expansion matches that of glass and ceramics, preventing stress cracks and maintaining airtight seals over temperature cycles.
2. Can 4J43 handle high-temperature applications?
Yes. With a Curie temperature around 420°C and stable thermal expansion up to 300°C, it withstands most high-precision hermetic environments.
3. What forms does DLX provide?
We supply plates, sheets, and strips with thickness from 0.1mm to 10mm and precise dimensional tolerances.
4. How does DLX verify thermal expansion properties?
Through independent thermal dilatometer testing and B-H loop analysis, verified by certified third-party laboratories.
5. Is 4J43 easy to machine and process?
Yes. The alloy is designed for standard machining, forming, and joining techniques, with minimal post-processing required.
6. What industries commonly use 4J43?
Aerospace, medical, electronic packaging, vacuum systems, and optical assemblies.
7. Does DLX provide technical support for application design?
Absolutely. Our engineers assist with matching expansion coefficients, material thickness selection, and process recommendations.
8. How is the quality of DLX 4J43 ensured?
Every batch is checked for composition, thermal expansion, tensile strength, and surface finish, with third-party verification available for critical applications.
Expert Insight
DLX Alloy’s 4J43 plates have been tested in real-world hermetic sealing applications, demonstrating superior reliability in vacuum electronics, aerospace instrumentation, and medical devices. Our clients have reported up to 20% reduction in seal failures when switching from conventional low-expansion materials to DLX 4J43 plates, validated by independent lab testing.
By combining controlled thermal expansion, high mechanical strength, and precision surface quality, DLX 4J43 ensures performance and durability in the most demanding hermetic environments, making it the material of choice for engineers seeking reliability and precision.
