TIG is a gas shielded arc welding with tungsten needles as arcs. Tungsten electrode, as a non melting electrode, requires high melting point, less volatilization and high temperature strength. The tungsten electrode is an ideal non melted electrode material because the melting point of tungsten is 3690K, the boiling point is 5900K, and the red heat intensity is high.

The pure tungsten electrode is the electrode without any addition of oxide. The power of electrode transgression is as high as 4.5ev. Requiring a high voltage for arc derivation. It has a low current capacity and easily burnt. Consequently, it is commonly used in condition of AC and low welding requirements. Tungsten electrodes widely used in the market are W-Th, W-Ce, W-Zr, W-Cs, W-Ba, W-La and so on. They are better than pure tungsten electrodes. The reasons are as follows:

1)High durability, long service life

2)Large current, Strong current carrying capacity

3)Good craft

In conclusion, pure tungsten is seldom used for TIG welding.