KOVAR 4J29: A Precision Fe-Ni-Co Alloy for Hard Glass Sealing Applications
KOVAR 4J29 is a high-performance Fe-Ni-Co (Iron-Nickel-Cobalt) series expandable alloy, specifically engineered for applications requiring precise thermal expansion properties to match with hard glass. Compliant with the YB/T 5231-2005 standard, KOVAR 4J29 is the go-to material for creating strong, reliable seals between metals and hard glass, widely used in various high-tech industries.
Key Features of KOVAR 4J29
Perfect for Glass Sealing:
KOVAR 4J29 is designed to have a thermal expansion rate that closely matches hard glass, ensuring a tight and durable seal under varying temperature conditions.
Thermal Expansion Precision:
Its carefully controlled chemical composition enables it to maintain consistent expansion properties, minimizing thermal stress between the metal and glass during temperature changes.
Chemical Composition
Element | C | P | S | Mn | Si | Cu | Cr | Mo | Ni | Co | Fe |
Content | ≤0.03 | ≤0.02 | ≤0.02 | ≤0.5 | ≤0.3 | ≤0.2 | ≤0.2 | ≤0.2 | 28.5~29.5 | 16.8~17.8 | Balance (Bal) |
KOVAR 4J29’s nickel content ranges from 28.5% to 29.5%, while cobalt is between 16.8% and 17.8%. The alloy contains minimal amounts of carbon, phosphorus, sulfur, manganese, silicon, copper, chromium, and molybdenum, carefully optimized to ensure superior performance in demanding sealing applications.
Applications
The primary use of KOVAR 4J29 is in sealing with hard glass, where its precise thermal expansion characteristics make it ideal for maintaining the integrity of seals in fluctuating temperature environments. Key industries utilizing KOVAR 4J29 include:
Electronics:
Used in hermetic seals for vacuum tubes, transistors, and other electronic components requiring metal-to-glass bonding.
Aerospace:
Essential in high-precision instruments and devices that must maintain airtight seals between metal and glass under varying pressure and temperature conditions.
Telecommunications:
Used in vacuum-sealed electronic devices and components to ensure long-term reliability and durability in harsh conditions.
Advantages
Precise Thermal Expansion:
The alloy’s expansion coefficient matches hard glass, reducing the risk of cracks and failures caused by thermal stress.
Excellent Sealing Properties:
KOVAR 4J29 forms strong, reliable seals, ensuring durability in high-stress environments where metal-to-glass bonding is required.
Corrosion and Oxidation Resistance:
The alloy’s chemical composition provides high resistance to oxidation and corrosion, even under extreme conditions, ensuring long-lasting performance.
Conclusion
KOVAR 4J29 is the industry-standard Fe-Ni-Co alloy for applications requiring precision sealing with hard glass. Its optimized chemical composition guarantees reliable performance in high-temperature and high-stress environments, making it indispensable for industries such as electronics, aerospace, and telecommunications. With its exceptional sealing properties and thermal expansion compatibility, KOVAR 4J29 ensures the durability and longevity of critical components.
This version highlights the alloy's chemical properties, key features, and advantages, presenting the information in a clear and informative manner for a technical audience.