Gas Tungsten Arc Welding (GTAW) or Tungsten Inert Gas (TIG) Welding

Gas tungsten arc welding  or GTAW  is the same as tungsten inert gas  or TIG  welding. It  is also an arc welding process. Here a non-consumable electrode is used. And most importantly - the electrode is made of  tungsten. And this electrode helps to produce the weld. The weld area is protected from atmospheric contamination or oxidation by usually an inert gas. This shielding gas is generally argon. Autogenous welds are not required in this process.
Here energy is supplied by a constant current welding power source. This power supply produces energy which is conducted through a column of ionized gas accompanied by metal vapors. These are known as plasma.

If this welding is done manually then it is one of the most complex welding processes. This process is difficult in industrial level because the welder has to maintain a short arc length. Great skill and care is needed to conduct the operation without any contact between electrode and workpiece. In GTAW the welder has to use both the hands. Welder has to put the filler metal manually and also maintain the torch. Some materials can be welded without the filler metal (autogenous or fusion).

Advantages of GTAW

• No flux is used
• No danger of flux entrapment when the welding of refrigerator or air conditioner takes place. 
•  Better control by the operator because of better visibility. 
• Very few splatters. Very high quality and smooth welds. 

Disadvantages of GTAW

• Under similiar conditions MIG welding is much more faster process. 
• Tungsten if gone to the molten weld then it can contaminate the pool. 
• Equipments  are costly. 

Applications

• Aluminium, magnesium, copper alloys can be welded easily. Inconel, carbon steels, stainless steels can be welded. 
• Thin parts and sheet metals can be welded easily. 
• Can sealing, instrument diaphragms and transistor cases can be welded very efficiently. 
• Expansion bellows and other delicate parts can joined. 
• Atomic energy, aircraft, chemical and instrument industries use this welding process. 
• Rocket motor chamber fabrication welding can be done by this process. 

Read :

• Different Types of Welding Defects 
• Advantages and disadvantages of Submerged Arc welding 
• Flux shielded metal arc welding process principle  
• Gas Metal Arc Welding (GMAW) or MIG Welding
• Submerged Arc Welding principle 
• Resistance Spot Welding Working Principles with merits and demerits 
• Resistance Seam Welding Advantages and Disadvantages