Doped Tungsten Wire

Doped tungsten wire is produced by introducing trace dopants such as K₂O, Al₂O₃, and SiO₂ into a high-purity tungsten matrix, followed by powder metallurgy processing, hydrogen reduction, multi-stage deformation, and controlled recrystallization. Stable dispersed phases and bubble-chain structures gradually form within the material during high-temperature sintering and subsequent processing. These microstructures constrain grain boundary migration during recrystallization, suppress abnormal grain growth, and increase resistance to dislocation movement. Based on CTIA’s production and customer service experience, these structural features primarily enhance creep resistance and sag resistance, allowing tungsten wire to maintain dimensional stability and shape retention under prolonged high-temperature service, making it well suited for applications requiring high structural stability.

1. Properties of Doped Tungsten Wire
The recrystallization temperature of doped tungsten wire is typically increased to approximately 1800–2200°C, providing better high-temperature strength retention and resistance to softening compared to pure tungsten wire. Tensile strength degrades more slowly within a typical operating range of 1800–2500°C, and electrical resistivity remains relatively stable, ensuring consistent thermo-electrical performance under long-term current loading. Its low vapor pressure also makes it suitable for high vacuum (10⁻³–10⁻⁷Pa) and inert atmosphere environments.

2. Dimensions of Doped Tungsten Wire
Common diameters range from φ0.01mm to φ3.0mm. Ultra-fine tungsten wire with diameters from 0.01 to 0.1 mm is mainly used in precision electron emission and sensing applications; tungsten wire from 0.1 to 1.0 mm is typically used for filaments and medium- to low-power heating elements; tungsten wire above 1.0 mm is applied in high-temperature structural components or high-power thermal field systems. Diameter tolerances are generally controlled within ±1%, with micro-scale wires reaching ±0.5μm. Strict requirements are also placed on roundness, diameter consistency, and coaxiality to ensure uniform tension and consistent heat distribution in multi-wire or array configurations.

3. Surface Condition of Doped Tungsten Wire
Surface conditions are generally classified as black tungsten wire and cleaned tungsten wire. Black tungsten wire retains an oxide film or residual lubricant, with relatively higher surface roughness, and is suitable for general heating and structural support. Cleaned tungsten wire, processed by electrolytic cleaning or chemical treatment, features higher surface cleanliness and lower impurity levels, making it more suitable for vacuum electronic devices, thermionic cathodes, and high-purity environments.

4. Applications of Doped Tungsten Wire
CTIA doped tungsten wire is widely used in incandescent and halogen lamp filaments to improve sag resistance and service life. In vacuum electronics, it is used in electron tubes, cathode assemblies, and emission filaments. In high-temperature equipment such as vacuum furnaces, electron beam heating systems, and evaporation coating equipment, it serves as heating elements or support structures. It is also applied in high-temperature sensing, scientific research, and precision thermal field control, where stable mechanical properties and dimensional consistency are required.

Doped tungsten wire achieves controlled recrystallization behavior at high temperatures through the combined effects of trace dopants and microstructures such as bubble chains and dispersed phases. This enables it to maintain relatively stable tensile strength, creep resistance, and dimensional consistency within the 1800–2500°C range, along with stable thermo-electrical performance in high vacuum and inert atmospheres. By optimizing dopant systems and processing routes, CTIA maintains tight control over diameter accuracy and batch consistency, and provides tungsten wire with customized specifications and surface conditions for high-temperature heating, electron emission, and precision structural applications.

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

WeChat: