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. ...Commonly called Tig, "Tungsten Inert Gas" Welding became an overnight success in the 1940's for joining magnesium and aluminum. The process was a highly attractive replacement for gas and manual metal arc welding. TIG has played a major role in the acceptance of aluminium for high quality welding and structural applications.

.....In the TIG process, the arc is formed between a pointed tungsten electrode and the workpiece in an inert atmosphere or argon or helium. The small intense arc provided by the pointed electrode is ideal for high quality and precision welding.

....The process utilizes a non-consumable electrode usually Tungsten, which is used to create an arc at the weld joint. Shielding is provided by an inert gas,typically Argon, Helium, or a mix gas. which is delivered at the weld location through the torch, which also holds the electrode. An arc is formed between the electrode and the components to be welded. The arc generates enough heat to create a molten pool. Filler wire can be introduced to the molten pool,but is not always necessary. The use of Filler wire is dependent on the type of joint being welded. Most metals and alloys can be welded by the tig process. The table below lists a number of the more common commercially available materials along with the most preferred polarity and current type.

.....TIG is applied in all industrial sectors but is especially suitable for high quality welding. In manual welding, the relatively small arc is ideal for thin sheet material or controlled penetration. Because deposition rate can be quite low, MIG may be preferable for thicker material and for fill passes in thick-wall pipe welds.