Product Overview

Kovar (an iron-nickel-cobalt alloy) (domestic equivalent: 4J29, American standard Kovar, Nilo K, UNS N14080) is a classic precision sealing alloy with a fixed expansion coefficient. Composed of iron, 29% nickel, and 17% cobalt, it features a high degree of matching with silicon-boron hard glass and special ceramics in terms of linear expansion coefficient, effectively resolving issues such as mismatched thermal expansion and contraction, gas leakage, and cracking between metals and non-metals. The alloy has a stable service temperature range of -60℃ to 450℃, with a Curie temperature of 430℃, maintaining stable structure at low temperatures and excellent sealing integrity at high temperatures. The alloy exhibits magnetic properties at room temperature but becomes non-magnetic above 430℃, making it the standard gas sealing material for electrical vacuum devices, precision electronics, and aerospace packaging.

Main Product Features

• Accurate expansion alignment, compatible with glass and ceramic sealing: Linear expansion coefficient remains stable and controllable within the range of 20～450°C, highly matching the expansion characteristics of silicon borosilicate glass and special ceramics, ensuring no stress cracking or loss of airtightness during the sealing process, enabling high-strength metal-glass and metal-ceramic gas-tight sealing.

• Stable organization, strong adaptability to high and low temperatures: The alloy has a high Curie temperature, with no phase transformation or performance突变 in the microstructure under conditions from room temperature to 450°C, no embrittlement or dimensional shift in low-temperature environments, and excellent thermal stability.

• Excellent process performance, suitable for precision processing: uniform and pure material, moderate hardness, good plasticity, capable of completing stamping, stretching, turning, bending, precision cutting, and other forming processes smoothly.

• Excellent airtightness and electromagnetic interference resistance: high material compactness, no loose air pores, achieving long-term high vacuum and high airtightness after sealing; effectively isolating external moisture, air, and impurities; the alloy remains non-magnetic above 430℃ to avoid electromagnetic interference issues under high-temperature conditions.

Product Detailed Parameters

Application Scope

Aerospace and Electron Vacuum Devices: Aerospace electron vacuum tubes, oscillator tubes, magnetron, ignitron, vacuum device casings, sealed bases, and lead components.

2. Precision Electronics and Semiconductor Packaging: Integrated circuits, transistors, diodes, chip packaging substrates, lead frames, sealed connectors, precision terminals.

3. Communication and RF Equipment: 5G high-frequency communication devices, RF packaging components, precision signal transmission sealed structures.

4. Precision Instruments & Medical Equipment: High-end precision sensors, sealing accessories for instruments and meters, anti-magnetic components for MRI medical equipment, precision measurement and control equipment encapsulation parts.

5. General high-end industrial: various glass-metal, ceramic-metal gas-tight joint components, vacuum equipment sealing parts, precision electrical insulation packaging accessories.

Frequently Asked Questions (FAQ)

• Q: What is the Curie temperature of Kovar alloy?

  A: The Curie temperature of Kovar alloy is 430°C.

• What is the linear expansion coefficient of Kovar alloy?

  A: The linear expansion coefficient of Kovar alloy is stable and controllable in the range of 20～450℃.

• A: What fields are Kovar alloys suitable for?

  A: Kovar alloy is suitable for aerospace, precision electronics, semiconductor packaging, communication and radio frequency equipment, precision instruments and medical equipment, as well as general high-end industries.