Product Description

4J28 alloy rod is an iron-nickel-cobalt (Fe-Ni-Co) controlled expansion alloy specially designed for glass-to-metal and ceramic-to-metal sealing applications. It has a linear expansion coefficient that precisely matches hard glass and ceramics, ensuring reliable hermetic sealing.

With stable mechanical strength, excellent machinability, and outstanding sealing performance, 4J28 rods are widely used in electronic packaging, vacuum devices, semiconductor components, and aerospace instruments.

Key Features

• Fe-Ni-Co alloy with controlled thermal expansion

• Excellent sealing performance with glass and ceramics

• Stable mechanical strength at various temperatures

• Easy machining and surface treatment

• Reliable long-term hermeticity

• Available in rods, wires, sheets, and customized forms

Typical Applications

• Glass-to-metal hermetic sealing

• Electronic packaging components

• Vacuum tubes and light bulbs

• Semiconductor packaging bases

• Aerospace and defense devices

• Sensor housings and feedthroughs