TIG welding, or otherwise known as Gas Tungsten Arc Welding (GTAW), is a welding process that uses a non-consumable electrode to join two pieces of metal by creating an arc. The arc heats the metal and the heat produced melts the metal together to form the weld. To make the job easier, a filler material is added to the weld joint, to elevate the weld strength.
TIG welding can be performed with a wide range of metals, however, it’s most commonly used for stainless steel, aluminum and copper alloys. It also has a wide range of uses; from welding thin tubes to spatially complicated assemblies.
TIG welding is more time consuming compared to other welding processes due to the time taken to adjust the current and the need to continuously add filler material, however, it produces clean and high-quality results. Due to the welds being smoother and providing high-quality strength, TIG welding is the preferred method used in aircraft construction and high-pressure piping.
In TIG welding, heat is produced by passing electricity with an arc length of 1.5 to 4mm between the tungsten electrode and the metal being welded. The electrode is usually made of tungsten, however, additional materials added with the addition of a second electrode, or a mixture of elements in the tungsten electrode resulting in a different characteristics and properties.
The most commonly used electrodes for welding aluminum and its alloys are 1% Thoriated tungsten and 2% Ceriated tungsten. The former and more popular option of the two, uses thorium to enhance the quality and consistency of the weld and due to its higher purity, it is more resistant against contamination and made from a higher concentration of sharp particles.
A second electrode, pure argon gas is used in TIG welding to shield the weld from oxidation. It also helps guide the arc intensity and prevent any contaminants from attacking the weld. The pure argon gas also provides a clean, consistent weld puddle.
Filler material is also used when TIG welding and is generally selected according to the type of metal being welded and the welding procedure being performed. Filler material comes in two main forms; tapes and wires. As the welding progresses, the filler material is added intermittently when needed to strengthen and smooth out the weld.
Finally, TIG welding requires a welding machine to generate the energy required for welding. Ann excellent welding machine will be one that is rated for higher currents and even better, is adjustable for different current ranges. This is critical for aluminium welding, as the requirements for aluminum are stricter than mild steel.
To summarize, TIG welding is a type of welding process that uses a non-consumable electrode to join two pieces of metal by creating an arc. It is by far one of the most difficult welding processes but produces clean and high-quality welds. Additional materials, such as a pure argon gas and filler material, are then added and the welding machine is to generate the energy required. TIG welding is renowned for being used in aircraft construction, high-pressure piping, and many common items like car and motorcycle parts.
