Product Overview

FeNi50 Iron-Nickel Fixed Expansion Precision Alloy is a high-purity fixed expansion precision sealing alloy in the iron-nickel series produced by Qinchuan New Materials (Zhengzhou) Co., Ltd. The alloy is formed through precise nickel-iron ratio melting, featuring a stable single austenite microstructure. The FeNi50 alloy has wide applications in electric vacuum devices, semiconductor packaging, aviation precision instruments, and high-end airtight components, and can solve industry challenges such as cracking, micro-leakage, and failure of metal-glass/ceramic sealing under temperature alternating working conditions.

Main Product Features

1. Precise determination of thermal expansion characteristics: FeNi50 alloy maintains linear, stable, and ultra-low thermal expansion coefficient within the core operating range of 20-400°C, achieving precise thermal expansion matching with borosilicate soft glass and special alumina ceramic, thereby eliminating issues such as cracking, micro-leakage, and delamination at the sealing interface.

2. High Stability in Organization: The alloy maintains a single pure austenitic structure throughout the temperature range from room temperature to medium temperature, without solid-state phase transformation, grain coarsening, or structural distortion, ensuring long-term stability of the microstructure.

3. Balanced Mechanical Properties: The alloy exhibits stable and balanced comprehensive mechanical properties, with tensile strength in the soft state ≥590MPa, elongation ≥30%, and hardness maintained at 180-220HV, combining excellent strength and ductility.

4. Wide compatibility with welding and processes: Excellent welding process performance, capable of various welding techniques such as brazing, spot welding, and argon arc welding, with smooth weld bead formation, high bonding strength, and no welding cracks or gas-tightness defects.

Product Detailed Parameters

Brand: Qinchuan New Materials

Origin: Zhengzhou

Function: Precision Sealing Connection

Part Material: Iron-Nickel Alloy

Product Model: FeNi50

Coefficient of thermal expansion: Average linear expansion coefficient is stably controlled at 9.2–10.0×10⁻⁶/℃ from 20 to 300℃, and within the range of 20 to 400℃, it is 9.2–9.9×10⁻⁶/℃.

Tensile strength: ≥590MPa

Tensile elongation: ≥30%

Hardness: 180–220HV

Long-term safe service temperature: ≤400℃

Short-term ultimate temperature tolerance: Up to 450℃

Application Scope

1. Electrical vacuum device sealing components: microwave tubes, vacuum tubes, cathode ray tubes, glass-metal sealed leads for vacuum relays, tube shells, sealed terminals.

2. Semiconductor and Microelectronic Packaging: Integrated circuit packaging bases, transistor cases, glass-to-metal sealed pins, precision vacuum feedthrough components.

3. Precision Aerospace Instruments: Aviation precision pressure diaphragms, sensor sealing shells, aviation special lamp sockets, precision dimension benchmark components.

4. High-end precision instruments and equipment: optical instrument components, precise metrological standard components, detection equipment sealing accessories, medical precision airtight components.

5. Special industrial sealing equipment: industrial vacuum equipment housing, vacuum valve seals, special light source electrode components, medium temperature precision sealing structural parts.

Frequently Asked Questions (FAQ)

Q: What is the coefficient of thermal expansion for FeNi50 alloy?

A: The average linear expansion coefficient of FeNi50 alloy is stably controlled at 9.2–10.0×10⁻⁶/℃ from 20 to 300°C, and 9.2–9.9×10⁻⁶/℃ from 20 to 400°C.

What are the welding processes for FeNi50 alloy?

A: The welding process for FeNi50 alloy includes brazing, spot welding, and argon arc welding, among other welding techniques.

Q: What is the applicable temperature range for FeNi50 alloy?

A: The long-term safe service temperature of FeNi50 alloy is ≤400℃, with a short-term maximum耐受 temperature of up to 450℃.