Tungsten Electrode as TIG Cathode Requirements

Tungsten electrode has high melting point, corrosion resistance, good thermal conductivity and electrical conductivity, so it is widely used in the field of welding. With the development of welding technology, tungsten electrode welding performance has gradually improved. Tungsten electrodes doped with the rare earth element to produce rare earth doped tungsten electrodes, so that the welding performance to be further developed. And common rare earth tungsten electrodes are including: cerium tungsten electrode, lanthanum tungsten electrode, zirconium tungsten electrode, and thorium tungsten electrode and so on.

Tungsten electrodes used in TIG should have following basic requirements:
1. High temperature resistance, electrodes should have good high temperature anti burning performance;
2. Electrode should have high electron emission capability;
3. Electrode should easy to arcing and can maintain stable arcing.

Pure tungsten electrode: its electron emission performance and anti-burning performance is poor, and service life is short, therefore less use in TIG welding. Pure tungsten electrode is good for broken in oxide film, so it is mainly used for AC welding of aluminum, magnesium and their alloys.

Thorium tungsten electrode: it has good electron emission properties, and the desired arc voltage is low, easy arcing and stable, with a good overall performance. However, it is radioactive, so people gradually turning to other type rare earth tungsten electrodes.

Cerium tungsten electrodes: Cerium tungsten electrodes have good thermal electron emission capability, stable arcing, heat concentration, long service life, and no radiation. At low current welding environment is the best alternative to thoriated tungsten electrode. Cerium tungsten electrodes commonly used in low current environment, mainly used for fine widget welding.

Lanthanum tungsten electrode: Lanthanum tungsten electrode has good mechanical cut property, creep resistance and high temperature performance, is the most popular electrode material. It is suitable for alternating current, and has excellent performance.

• < Prev
• Next >