Why Is Pure Tungsten Rarely Used In Argon Tungsten Arc Welding?

Nov 05, 2020

Tungsten argon welding (TIG) is a gas shielded welding with a tungsten needle as one pole of the arc. As a non-melting electrode, tungsten electrode is required to have a high melting point, low high temperature volatilization and high high temperature strength! Tungsten has a melting point of 3690K and a boiling point of 5900K. It has high red heat strength and is an ideal non-melting electrode material.

The widely used thorium tungsten (W-Th), cerium tungsten (W-Ce), zirconium tungsten (W-Zr), cesium tungsten (W-Cs), barium tungsten (W-Ba), lanthanum tungsten (W- La), etc., their current-carrying capacity, arc ignition performance and service life are better than pure tungsten; mainly because their work function is lower than pure tungsten, so that they have high durability, long life, and burn damage The rate drops and the number of tungsten electrode grinding times decreases. ②The allowable current is large and the current carrying capacity is enhanced. ③Good manufacturability, strong electron emission capability of tungsten electrode, reliable arc ignition, stable arc, and low no-load voltage.

It is worth noting that ①The trace of thorium contained in thorium and tungsten is a radioactive element, which is harmful to health, so try to substitute cerium tungsten and lanthanum tungsten. ②Pure tungsten is not a bad choice when welding aluminum.

In short, pure tungsten is rarely used in practical applications due to the above-mentioned reasons.