Iron-Nickel Controlled Expansion Alloys
These alloys feature a CTE matched to hard glass and alumina/aluminum nitride ceramics across a broad temperature range. They serve as base materials for ceramic-to-metal and glass-to-metal hermetic sealing in vacuum electronic devices, microwave components, and hybrid integrated circuits.
Technical data
| Products: | 4J29 (Kovar), 4J42（42 alloy）, 4J45, 4J50（FeNi50）, 4J52（FeNi52）, 4J54 | Form: | Strip, wire, flat wire |
| Strip Thickness: | ≥0.02 mm | Wire Diameter: | ≥0.03mm |
| Performance: | Customized |
Features & Benefits
Precise CTE Matching
The nickel content is controlled from 29% to 52% to achieve CTE matching with hard glass, borosilicate glass, and alumina/aluminum nitride ceramics, while preventing the risk of seal cracking.
Hermetic Sealing
Forms high-strength, leak-free glass-to-metal or ceramic-to-metal seals under high-vacuum and severe thermal cycling conditions.
Metallurgical Stability
Features a uniform and stable microstructure for long-term operation with minimal dimensional drift, meeting the requirements of high-reliability systems.
Surface Compatibility
Demonstrates good wettability with brazing alloys such as AgCu and AuNi, as well as molten glass, forming a solid metallurgical bond with minimal risk of delamination.
Broad Processing Adaptability
Available in strips, wires, and rods; designed for stamping, deep drawing, and CNC machining for complex packaging structures.
