Pure Tungsten Electrodes
Because of its high melting point, Tungsten is used to manufacture tungsten inert gas (TIG) electrodes. Tungsten electrode is made of materials with high melting point, corrosion resistance, high density, good thermal conductivity and conductivity. Tungsten electrode includes pure tungsten electrode and tungsten alloy electrode. Pure tungsten electrode contains at least 99.50% of tungsten. Tungsten alloy electrodes are made of tungsten, other elements and their oxides. Tungsten alloy electrodes include ceriated tungsten electrode, lanthanated tungsten electrode, etc. Adding rare earth oxide to tungsten metal can reduce its escaping power, enhance the ability of electron emission, and improve the welding performance of tungsten electrode: better arcing performance of electrode, higher stability of arc column, and lower electrode burn rate. Different kinds and different sizes of electrodes are used for different types of welding and different types of materials. Some electrodes work well under alternating current (AC) while others work better under direct current (DC). So different electrodes are chosen for different purposes.
The tungsten content of pure tungsten electrode is at least 99.5%. There is no alloy element in pure tungsten electrode. Pure tungsten electrode has superior performance: low steam pressure, low resistance, good electric conductivity, small thermal expansion, high elastic modulus. It is generally used for welding aluminum and magnesium alloy under alternating current (AC).