Gas tungsten arc welding (GTAW) is the welding process that uses a non-consumable electrode. In this process, a tungsten electrode is used to create an electric arc between the electrode and the workpiece. The electrode does not melt during the welding process and therefore does not contribute to the filler material.

Gas tungsten arc welding (GTAW) can also be referred to as tungsten inert gas (TIG) welding. It is a versatile welding process that can be used to weld a wide range of materials including stainless steel, aluminum, and copper alloys.

Here is a detailed explanation of the process:

- Equipment and setup: In GTAW, a welding machine is used to supply the necessary power for the welding process. The machine provides a constant current output that can be adjusted to control the heat input. The machine is also equipped with a gas supply system that provides a shielding gas to protect the weld pool from atmospheric contamination.

- Electrode: The electrode used in GTAW is made of tungsten, which has a high melting point. The electrode is held in a torch and is connected to the welding machine through a cable. The electrode does not melt during the welding process and therefore remains constant in length.

- Shielding gas: A shielding gas, such as argon or helium, is used to protect the weld pool from atmospheric contamination. The gas is supplied through the torch and forms a protective shield around the welding area. The choice of shielding gas depends on the material being welded and the desired welding characteristics.

- Welding process: In GTAW, the electrode is brought close to the workpiece and an electric arc is created by striking the electrode against the workpiece. The arc creates a high temperature that melts the workpiece and forms a weld pool. The electrode does not melt during the process and acts as a heat source.

- Filler material: In some cases, a filler material may be added to the weld pool to achieve the desired weld strength and appearance. The filler material is typically in the form of a wire that is manually fed into the weld pool. The filler material is separate from the electrode and is not consumed during the welding process.

Overall, gas tungsten arc welding (GTAW) is a precise and versatile welding process that is commonly used in industries such as aerospace, automotive, and fabrication. Its use of a non-consumable electrode makes it suitable for welding materials that require a high level of precision and control.