1. Excellent high temperature resistance. The electrode will not melt and burn during welding. Otherwise, not only the electrode itself will be consumed quickly, but also the arc will drift, resulting in arc instability. In addition, once the electrode is melted, the electrode material entering the weld pool will pollute the weld, produce welding defects, and affect the quality of the weld.
2. Strong ability to emit electrons. The escape work of the electrode material is small. Especially at high temperatures, it should have a strong ability to emit hot electrons.
3. Large current carrying capacity. The electrode should have good electrical and thermal conductivity and can carry large current without overheating.
4. Good grinding performance. The surface of the electrode needs to be ground to have a certain dimensional accuracy and end Angle, so as to ensure the clamping accuracy of the electrode and reliable conduction, maintain the stability of the arc, and improve the concentration of the arc heat.
5. Low radioactivity. Some substances used to improve the ability of electrodes to emit electrons are radioactive, which is harmful to the human body, so electrode materials with small radioactivity should be selected.

Secondly, thorium tungsten electrode can be formed by adding 1 percent ~ 2 percent thorium oxide (ThO) to pure tungsten. This can greatly reduce the escape work of the electrode, significantly enhance the electron emission ability, and improve the arc initiation and arc stability of the electrode, but also improve the current carrying capacity of the electrode and extend the service life of the electrode. However, the small amount of ThO2 contained in thorium tungsten electrode is highly radioactive, so it is not used much at present.

Finally, to reduce the radioactivity of the electrode, we use less radioactive cerium (Ce) instead of thorium. Practice has proved that adding cerium oxide (CeO) with a mass fraction of about 2 percent to pure tungsten can also significantly reduce the escape work of the electrode and improve the arc initiation and arc stability of the electrode. Especially in the small current welding, the arc heat of cerium tungsten electrode is more concentrated, and the burning rate of electrode is reduced. However, in high current welding, the anti-overheating ability of cerium tungsten electrode is not as good as that of pin tungsten electrode. Cerium tungsten electrode is a promising electrode material because of its weak radioactivity and little harm to human body.