Final answer:
The GTAW electrode is made from tungsten because of tungsten's high melting point, resistance to thermal expansion and corrosion, and its ability to remain inert during welding, which ensures the stability and longevity of the electrode.
Step-by-step explanation:
Why is the GTAW Electrode Made from Tungsten?
The GTAW (Gas Tungsten Arc Welding) electrode is made from tungsten or tungsten alloys due to several of its material properties. Tungsten has an exceptionally high melting point, making it ideal for withstanding the intense temperatures encountered during the welding process. This prevents the electrode from melting. Additionally, tungsten's strong resistance to thermal expansion and corrosion contributes to a stable arc and longevity of the electrode. Tungsten also emits a balanced white light when heated, indicating that it can reach high temperatures without degrading, which is another reason why it's commonly used for filaments in light bulbs. It is important to note that, like other transition metals, tungsten does not easily undergo chemical transformations during high-energy processes, hence it remains inert and does not affect the makeup of the materials being welded, a characteristic that is highly desirable in electrodes for GTAW.