Explain TIG (GTAW) welding process with neat sketch.
Tungsten Inert Gas Arc Welding (TIG, GTAW): It is a welding process, in which heat is generated by an electric arc struck between a nonconsumable tungsten electrode and the work piece. The weld pool is shielded by an inert gas (Argon, helium, Nitrogen) protecting the molten metal from atmospheric contamination. The heat produced by the arc melts the work pieces edges and joins them. Filler rod may be used, if required. Tungsten Inert Gas Arc Welding produces a high quality weld of most of metals. Flux is not used in the process.