Ultra Fine Tungsten Wire

Ultra fine tungsten wire refers to tungsten wire with micron-scale diameters, typically ≤φ10 μm, and further refined to 1–5 μm or below for precision applications. As the size reaches the micron scale, material performance is influenced not only by tungsten itself but also by size effects, surface condition, and processing. CTIA views ultra fine tungsten wire not merely as a size reduction, but as a result of comprehensive control over raw material purity, microstructure, and process stability.

1. Properties of Ultra Fine Tungsten Wire
Tungsten features a high melting point, high density, and low vapor pressure, ensuring thermal stability in high-temperature and vacuum environments. Ultra fine tungsten wire offers low heat capacity and rapid thermal response with an extremely small cross-section and high surface area-to-volume ratio. Its resistivity is approximately 5.6×10⁻⁸ Ω·m at room temperature, enabling effective Joule heating at relatively low current. However, its limited cross-section results in lower mechanical strength and creep resistance, making it more suitable for light-load or non-structural applications.

2. Specifications of Ultra Fine Tungsten Wire
Ultra fine tungsten wire is classified by diameter:

2.1 φ5–10 μm: fine range balancing strength and processability, used in micro filaments, vacuum electronic devices, and general micro heating elements.
2.2 φ1–5 μm: typical ultra fine range, widely used in electron emission sources, localized heating, and precision sensors.
2.3 ≤1 μm: micron or sub-micron range, mainly used in research and specialized applications, such as Scanning Probe Microscope (SPM) probes, electron microscopy electrodes, and nano-scale structures, etc.

3. Surface Condition of Ultra Fine Tungsten Wire
Ultra fine tungsten wire is available in black tungsten wire and cleaned tungsten wire. Black tungsten wire retains the oxide layer formed during drawing and annealing, resulting in a relatively rough surface, while cleaned tungsten wire undergoes chemical or electrolytic treatment to remove oxides and impurities, achieving higher cleanliness. Due to the extremely small diameter and high surface area, surface condition significantly affects resistance distribution, heating uniformity, and emission stability. Cleaned tungsten wire is generally preferred to reduce contamination and improve system stability for vacuum and electron emission applications.

4. Applications of Ultra Fine Tungsten Wire
Ultra fine tungsten wire is mainly used in precision applications requiring strict control over size, response speed, and stability:

4.1 Electron Emission and Vacuum Devices
Used in micro filaments, thermionic cathodes, and electron source structures, operating in high vacuum environments (≤10⁻⁵ Pa) with high requirements for surface cleanliness and structural consistency.

4.2 Localized Heating
Used as micro heating elements or localized heat sources, enabling millisecond-level response for precision thermal processing and localized energy input.

4.3 Precision Measurement and Sensing
Used as micro thermal elements or high-temperature sensing materials, enabling high-sensitivity measurement in space-constrained or low-gradient environments.

4.4 Microstructures and Research Applications
Used as micro electrodes, support structures, or experimental components in micro/nano fabrication and material research.

4.5 Optoelectronic and Semiconductor Equipment
Used in heating and conductive components for light source systems and semiconductor processing equipment, providing stable electrothermal performance in clean environments.

4.6 Electron Beam and Vacuum Coating Equipment
Used as heating filaments and auxiliary structural components in electron beam evaporation and vacuum coating systems, maintaining shape stability under high temperature and vacuum conditions.

For sourcing decisions, CTIA recommends a comprehensive evaluation of diameter, surface condition, material system, and service environment, while balancing vacuum level, temperature range, and current density. CTIA ensures reliable and consistent performance at the micron scale by controlling material purity, microstructure, and dimensional consistency, meeting the requirements of precision applications for stability and long-term operation.

For any inquiry, please contact tungsten wire manufacturer: CTIA GROUP

Email: sales@chinatungsten.com

Tel: 0086 592 5129696 / 0086 592 5129595

Website: www.tungsten.com.cn

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