Product Overview

FeNi50 Iron-Nickel Fixed Expansion Precision Alloy is a high-purity fixed expansion precision seal alloy 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 a wide range of 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

Precisely determine expansion characteristics: FeNi50 alloy maintains linear, stable, and ultra-low thermal expansion coefficient in the core working condition range of 20-400°C, achieving precise thermal expansion matching with borosilicate soft glass and special alumina ceramic, thereby preventing cracking, micro-leakage, and peeling problems at the sealing interface.

2. High Stability in Organization: The alloy maintains a single, pure austenitic microstructure throughout the temperature range from room temperature to medium temperature, with no solid-state phase transformation, no grain coarsening, and no 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 plasticity.

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 9.2–9.9×10⁻⁶/℃ from 20 to 400℃.

Tensile strength: ≥590MPa

Tensile elongation: ≥30%

Hardness: 180-220HV

Long-term safe service temperature: ≤400℃

Short-term limit temperature: Up to 450℃

Application Scope

Vacuum Device Sealing Components: Microwave tubes, vacuum tubes, picture tubes, glass-to-metal sealed leads for vacuum relays, tube shells, sealed terminals.

2. Semiconductor & Microelectronics Packaging: Integrated circuit packaging substrates, transistor casings, glass-to-metal sealed pins, precision vacuum feedthrough components.

3. Precision Instrumentation for Aerospace: Aviation precision pressure diaphragms, sensor sealed housing, aviation special lamp sockets, precision dimensioning standard components.

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

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

Frequently Asked Questions (FAQ)

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℃, and 9.2-9.9×10⁻⁶/℃ from 20 to 400℃.

Q: 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°C, with a short-term ultimate resistance temperature up to 450°C.