When using the GTAW welding process with AC current, the tungsten end will be?

In GTAW, or Gas Tungsten Arc Welding, the nature of the tungsten electrode is influenced by the type of current used. When using alternating current (AC), the tungsten electrode typically takes on a "ball" shape at the end. This occurs because, during the AC cycle, the electrode experiences a combination of oxidation and melting.

AC current alternates the polarity, which allows for the cleaning action of the electrode. As the positive phase passes, the tungsten heats up and partially melts, forming a rounded, ball-like shape at the tip. This spherical shape is beneficial because it helps maintain an even arc and provides a broader area for the arc to stabilize during the welding process.

In contrast, with direct current, especially in DC electrode negative, the tungsten tip remains sharp or pointed, which helps in achieving a more focused arc. However, in AC conditions, the balled tip results in better arc stability and more efficient welding operations. Thus, a balled tungsten end is characteristic of the GTAW process when working with AC current.