Which type of electrode is preferred for GTAW due to its high melting point?

The preferred electrode for Gas Tungsten Arc Welding (GTAW) due to its high melting point is tungsten. Tungsten is a refractory metal that has a melting point of approximately 3,422 degrees Celsius (6,192 degrees Fahrenheit), which allows it to maintain its integrity and shape during the welding process, even at the high temperatures produced during arc welding. This property makes it particularly suitable for GTAW, where the arc is established between the tungsten electrode and the workpiece.

Tungsten electrodes also provide excellent electrical conductivity and can produce a stable arc, which is crucial for achieving high-quality welds. Additionally, tungsten's ability to withstand contamination and its chemical inertness ensure that it does not adversely affect the weld pool, leading to cleaner and more precise welds.

In contrast, the other materials listed do not have the same combination of high melting point and desirable welding characteristics as tungsten. Copper, while a good conductor, cannot withstand the temperatures encountered in GTAW due to its lower melting point. Carbon and aluminum also fall short, with aluminum being widely used in other welding processes but not well-suited for the stringent requirements of GTAW. Therefore, tungsten's properties make it the ideal choice for electrodes in this welding technique.