These electrodes are used mainly with alternating current (AC) for welding of aluminum and magnesium alloys.
With this type of current, the tip of the EWP electrode forms a clean, balled end, which provides good arc stability.
Pure tungsten is the least expensive, but is more prone to contamination of the weld than the other types of tungsten electrodes.
Pure Tungsten Welding Electrodes.| The EWP electrodes are unalloyed tungsten electrodes (99.5 percent tungsten minimum). Their current-carrying capacity is lower than that of other electrodes. They provide good stability when used with alternating current, either balanced wave or continuously high frequency stabilized. They may be used with direct current with either argon or helium, or a combination of both, as a shielding gas. They maintain a clean, balled end, which is preferred for aluminum and magnesium welding. These electrodes have reasonably good resistance to contamination of the weld metal by the electrode, although the oxide containing electrodes are superior in this respect. EWP electrodes are generally used on less critical applications, except for welding aluminum and magnesium.