Gas discharge lamps, such as high-pressure mercury lamps and xenon lamps, play an important role in industrial lighting, stage lighting, automotive headlights, and other fields. As a key electrode material, tungsten wire is a core element in ensuring the stable and efficient operation of gas discharge lamps.
Tungsten wire has an extremely high melting point of approximately 3410°C, enabling it to withstand the extremely high temperatures of gas discharge lamp operation. During the gas discharge process, a large amount of heat is generated around the electrode, and the energy is highly concentrated. While ordinary metals would quickly melt at such high temperatures, tungsten wire remains solid, maintaining the stability of the electrode structure. Furthermore, the atomic structure of tungsten wire remains relatively stable even in high-temperature environments, preventing it from easily diffusing or undergoing phase changes due to overheating. This ensures a continuous and stable flow of current, thus enabling continuous gas discharge.
Tungsten wire also exhibits excellent electrical conductivity. Despite its higher resistivity than some metals, tungsten wires effectively conduct current under the specific operating conditions of HID lamps, providing the necessary energy for gas ionization. Furthermore, tungsten wires maintain good mechanical strength even at high temperatures and are resistant to deformation or breakage. This ensures electrode reliability over extended use and reduces HID lamp failures caused by electrode damage.
To further enhance the performance of tungsten wires in HID lamps, they are often treated with special treatments. For example, doping with other elements improves the tungsten wire's recrystallization properties, slowing embrittlement caused by grain growth at high temperatures. Alternatively, coating the tungsten wire with a special material enhances its resistance to electron bombardment and chemical corrosion.
