The 4J series, which includes 4J42, 4J50, and 4J52, are high-performance Fe-Ni (Iron-Nickel) expandable alloys. These alloys are designed to match the thermal expansion properties of soft glass and ceramics, ensuring reliable sealing and excellent performance in high-stress environments. All three grades conform to the YB/T 5235-2005 standard, making them ideal for precision applications across various industries.
Key Features of 4J42, 4J50, and 4J52
Optimized for Soft Glass and Ceramic Sealing:
The 4J series alloys are engineered to have precise thermal expansion coefficients that closely match soft glass and ceramic materials, ensuring strong, durable seals.
Thermal Stability:
All three alloys in the series exhibit excellent thermal stability, reducing stress caused by thermal expansion, which is critical in applications where temperature variations are common.
Chemical Composition
Grade | C | P | S | Mn | Si | Al | Co | Ni | Fe |
4J42 | ≤0.05 | ≤0.02 | ≤0.02 | ≤0.8 | ≤0.3 | ≤0.1 | ≤1 | 41.0~42.5 | Balance (Bal) |
4J50 | ≤0.05 | ≤0.02 | ≤0.02 | ≤0.8 | ≤0.3 | --- | --- | 49.5~50.5 | Balance (Bal) |
4J52 | ≤0.05 | ≤0.02 | ≤0.02 | ≤0.8 | ≤0.3 | --- | --- | 51.5~52.5 | Balance (Bal) |
The primary difference between these three grades is their nickel content. 4J42 contains 41.0% to 42.5% nickel, 4J50 has 49.5% to 50.5% nickel, and 4J52 includes 51.5% to 52.5% nickel. Each alloy is optimized for specific applications requiring different thermal expansion properties.
Applications
The 4J42, 4J50, and 4J52 alloys are primarily used in applications where a matching seal with soft glass or ceramic is required. These alloys find their place in industries such as:
Electronics:
Used in hermetic seals, connectors, and feedthroughs where metal must bond with soft glass or ceramics, protecting electronic components from environmental damage.
Aerospace:
These alloys are employed in high-precision instruments and components where metal-to-glass or metal-to-ceramic seals must withstand extreme conditions.
Telecommunications:
Used in vacuum tubes, microwave devices, and other sensitive components where maintaining a hermetic seal between metal and soft glass is crucial.
Medical Devices:
These alloys are used in medical equipment that requires precision sealing between metal and glass or ceramic components, ensuring reliability and longevity.
Advantages
Precise Thermal Expansion Matching:
The carefully controlled nickel content in each grade ensures that these alloys have a thermal expansion coefficient closely aligned with that of soft glass and ceramics, minimizing the risk of cracks and failures caused by thermal stress.
Durability in Extreme Conditions:
These alloys maintain their mechanical properties and performance in harsh environments, including high-temperature and corrosive conditions, ensuring long-lasting reliability.
Corrosion Resistance:
The 4J series alloys are highly resistant to corrosion, especially in demanding environments where seals are exposed to temperature fluctuations and chemical exposure.
Conclusion
The 4J42, 4J50, and 4J52 alloys are essential materials for industries requiring precise and reliable sealing between metals and soft glass or ceramic components. Their excellent thermal expansion properties, high durability, and corrosion resistance make them ideal for use in electronics, aerospace, telecommunications, and medical devices. With their optimized nickel content and stable performance in extreme conditions, these alloys ensure long-term reliability in even the most demanding applications.
This version highlights the key features, chemical properties, and advantages of each alloy while explaining the relevant application areas in a clear and professional tone.