What type of current is commonly used in GTAW?

GTAW, or Gas Tungsten Arc Welding, utilizes both direct current (DC) and alternating current (AC), making the understanding of different power sources crucial for this welding process. The choice of current type can affect the welding characteristics and is often determined by the materials being welded.

Direct current is typically used for welding ferrous metals and non-ferrous metals, such as stainless steel and aluminum. It provides more stability and a focused arc, which is especially beneficial for thicker materials and when performing intricate welds.

On the other hand, alternating current is essential when welding aluminum and magnesium. These materials often form an oxide layer that can impede the welding process. The alternating current helps in breaking up this oxide layer, allowing for a cleaner weld.

By understanding that both current types play significant roles in various welding scenarios, welders can tailor their approach based on the materials and desired outcomes. This versatility helps ensure that the welding process is effective, thereby showcasing why the option indicating the use of both DC and AC is the most accurate.