Argon can effectively isolate the surrounding air. It is insoluble in metals and does not react with metals. In the process of tungsten argon arc welding, the arc also has the function of automatically removing the oxide film on the workpiece surface. Therefore, it can successfully weld non-ferrous metals, stainless steels and various alloys that are easy to oxidize, nitride and have strong chemical activity.
Tungsten arc is stable. It can burn stably even at a small welding current (< 10A). It is especially suitable for welding thin and ultra-thin plates.
The heat source and filler wire can be controlled separately, so the heat input can be easily adjusted, and welding at various positions can be carried out.
Due to the protection of argon, the harmful effect of air on molten metals can be isolated. Therefore, TIG welding is widely used to weld non-ferrous metals such as aluminum, magnesium and their alloys, stainless steel, superalloys, titanium and titanium alloys that are easy to oxidize, as well as refractory active metals such as molybdenum, niobium and zirconium.
For more common materials such as carbon steel and low-alloy steel, TIG welding is generally not adopted except for occasions requiring high welding quality.