How is the heat distribution characterized in GTAW?

In Gas Tungsten Arc Welding (GTAW), the heat distribution is significantly influenced by the current mode used, such as direct current electrode negative (DCEN) or alternating current (AC). The current mode affects the amount of heat generated at the workpiece compared to the tungsten electrode. For DCEN, the majority of the heat is concentrated on the workpiece, making it effective for welding most metals. In contrast, AC can help balance heat distribution and is particularly useful for aluminum and magnesium, as it allows for both the cleaning of the oxide layer and effective penetration. Therefore, understanding how different current modes alter heat distribution is crucial for achieving the desired weld characteristics and ensuring quality welds.