Ultra-high Melting Point (3422°C): This is the fundamental reason. When used as a filament, it needs to operate stably and emit light at high temperatures (around 2500–3000°C for incandescent bulbs). Tungsten is the only practical metal capable of withstanding such temperatures over a long period.
Low Evaporation Rate (at High Temperatures): Tungsten has a relatively low evaporation rate at elevated temperatures, which directly determines the service life of incandescent lamp filaments. Evaporation will cause the filament to thin and break, and also lead to blackening on the inner wall of the bulb.
High Electrical Resistivity: The optimal resistivity allows it to achieve the required resistance value in a limited size, facilitating the conversion of electricity to heat to light.
Excellent High-temperature Strength and Creep Resistance: It can maintain its shape at high temperatures without being prone to softening or sagging, which is crucial for preserving the filament structure.
Good Ductility (Post-processing): Pure tungsten is brittle, but through special doping and processing techniques, it can be fabricated into extremely thin filaments (down to the micrometer scale) with great length and a certain degree of toughness.
Lighting and Electro-vacuum Industry (Traditional Core Application)
Incandescent/Halogen Lamp Filaments: Wound into single or double helix structures to reduce heat loss and improve luminous efficiency. The halogen regenerative cycle effectively slows down tungsten evaporation.
Gas Discharge Lamp Electrodes: Used in high-pressure sodium lamps, metal halide lamps, etc., serving as the core component for electron emission.
Heaters (Filaments) for Vacuum Tubes and Electron Tubes: Heat the cathode to enable electron emission.
High-temperature Industry and Heat Treatment
High-temperature Furnace Heating Elements: Wound into mesh or spiral shapes and used as resistance heating components in high-temperature furnaces under vacuum or hydrogen protection, with an operating temperature up to 3000°C.
Thermal Field Supports and Connectors: Applied in single crystal furnaces, sintering furnaces, etc.
Electronics and Semiconductor Industry
Semiconductor Device Gates: Used in some older or special electronic devices.
Probes and Connecting Wires: Applied for precision testing.
Ion Implanter Components: Withstand high-temperature and corrosive environments.
Additive Manufacturing (3D Printing)
Powder Spreading Blades for metal 3D printing technologies such as Electron Beam Melting (EBM) and Selective Laser Melting (SLM): Thanks to its high hardness, high-temperature strength and excellent wear resistance, it can stably push high-temperature metal powders.
Other Special Applications
Cutting Wires: Used as electrode wires in wire-cut electrical discharge machines for cutting cemented carbide, gemstones, etc.
Reinforcing Fibers for Composite Materials: Applied in the preparation of high-performance tungsten wire/superalloy composites.
Microscope Sample Holders.
String Cores for Musical Instruments (Guitars, Pianos): Provide high density and a unique timbre.
English