Fe Ni Co Alloy Pipe Kovar 4J29 Tube For Aerospace Field

Good Stability Fe Ni Co Alloy Pipe Kovar 4J29 Tube For Aerospace Field

Product Introduction

Kovar 4J29 tube is a type of iron-nickel-cobalt alloy tubing with a low coefficient of thermal expansion. It is widely used in electronic packaging, aerospace, and precision instruments. The main components include approximately 29% nickel, 17% cobalt, and the remainder iron, along with trace amounts of silicon, manganese, and other elements. This alloy has a linear expansion coefficient similar to that of borosilicate hard glass, around 4.6×10⁻⁶/℃, within the temperature range of 20℃ to 450℃. It also has a high Curie point and good low-temperature structural stability. The oxide film of Kovar 4J29 tube is dense and can be well wetted by glass. Moreover, it does not react with mercury, making it suitable for use in instruments with mercury discharge. Its density is 8.36 g/cm³, electrical resistivity is 48-52 μΩ·cm, and thermal conductivity is 17 W/(m·K). At room temperature, it has a high magnetic permeability. After specific heat treatment, the magnetic hysteresis loss can be significantly reduced. The mechanical properties of Kovar 4J29 tube exhibit good strength and toughness, with a tensile strength typically ranging from 450 to 550 MPa, elongation of 30%-40%, and hardness between HB140 and 180. This alloy tubing has good machinability, with excellent machinability and formability. Common machining methods include turning, milling, drilling, etc. In addition, it has good weldability, usually employing high-energy-density welding methods such as laser welding, electron beam welding, or brazing. These characteristics make Kovar 4J29 tube an ideal material for manufacturing parts with high precision and strength requirements, especially in applications where sealing connections with glass or ceramics are needed.

Parameter

Specific Applications

1. Satellite components: Kovar 4J29 Tube is used to manufacture structural components and connection parts in satellites, ensuring stability and reliability under extreme temperature changes and high vacuum conditions.
2. Aircraft instruments and engine parts: In the instrument systems and engine parts of aircraft, Kovar 4J29 Tube, due to its low coefficient of thermal expansion and high strength characteristics, can effectively reduce thermal stress and ensure the long-term stable operation of equipment.
3. Structural components of missiles and spacecraft: Kovar 4J29 Tube is used to manufacture high-temperature parts of missiles and spacecraft, such as turbine blades and combustion chambers, because of its high-temperature and corrosion resistance in extreme environments.
4. Navigation instruments and aerospace devices: In the aerospace field, Kovar 4J29 Tube is widely used in navigation instruments and aerospace devices to meet the requirements of precision and stability.

Advantages and Characteristics

• Low coefficient of thermal expansion: The thermal expansion coefficient of Kovar 4J29 Tube is approximately 5.1×10⁻⁶/°C in the temperature range of 20℃ to 450℃, which matches well with the thermal expansion coefficients of glass and ceramics. This enables it to effectively avoid structural stress caused by mismatched thermal expansion in high-precision assemblies.
• Good mechanical properties: Kovar 4J29 Tube has high strength and good ductility, with a tensile strength usually ranging from 450 to 550 MPa, elongation of 30%-40%, and hardness between HB140 and 180. This strength and toughness allow it to adapt to various machining methods and have a wide range of applications in the manufacturing of aerospace equipment.
• Excellent electrical properties: The electrical resistivity of Kovar 4J29 Tube is relatively low, typically about 10% of that of electrolytic copper. This characteristic makes it suitable for high-precision electronic devices, especially in environments where low electrical conductivity but good stability are required.
• Good machinability: Kovar 4J29 Tube has good machinability and formability. Common machining methods include turning, milling, drilling, etc. It can maintain high dimensional stability during these machining processes. For the production of precision parts, especially in fields with strict requirements on thermal expansion characteristics, precision machining can ensure the high precision and reliability of components.

Performance:

The fatigue performance of Kovar 4J29 Kovar 4J29 has good fatigue performance and can withstand repeated stress without easy fracture. Experimental results show that the fatigue limit of 4J29 alloy is about 260 MPa at room temperature, while it decreases to around 200 MPa under high temperature (500°C) conditions. Therefore, it is necessary to reasonably control the applied stress in design and use to ensure the long-term stability of the material.

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Q&A

What is the fatigue performance of Kovar 4J29?

Kovar 4J29 has good fatigue performance and can withstand repeated stress without easy fracture.

What are the surface treatment methods for Kovar 4J29?

Kovar 4J29 can undergo surface treatments such as electroplating, oxidation, and sandblasting to enhance its surface properties and aesthetics.

What is the dimensional accuracy of Kovar 4J29?

Kovar 4J29 can achieve high dimensional accuracy through precision machining techniques, typically reaching IT5-IT6 grade.

What are the supply forms of Kovar 4J29? Kovar 4J29 is usually supplied in forms such as bars, plates, tubes, wires, and strips to meet the needs of different application scenarios.