TIG welding (Tungsten Inert Gas) is a type of welding that is highly demanded and well priced in the labor field. It uses alternating current and is characterized by the use of a permanent tungsten electrode. Sometimes we can find it alloyed with thorium or zirconium in percentages no higher than 2%. At present, thorium is prohibited as it is an element that is considerably harmful to health. Tungsten due to the high melting temperature of 3,410 ° C hardly wear after prolonged use. The most commonly used gases are Aragon and helium, or a mixture of both.
The main advantage of the TIG is the obtaining of more resistant, ductile and less corrosion sensitive strips than in the rest of the procedures, since the protective gas prevents the contact between the oxygen of the atmosphere and the fusion bath. It also allows to obtain clean and uniform welds due to the shortage of fumes and projections.
As a disadvantage we can find the continuous flow of gas, with the subsequent installation of pipes, cylinders, etc. In addition, it requires a highly specialized workforce, which also increases costs.
MIG welding (Metal Inert Gas) is a process of arc welding, under protective gas with consumable electrode. The arch is formed by a continuous thread and the pieces to be joined. This welding is intrinsically more productive than MMA welding where part of the productivity is lost every time a stop occurs to replenish the electrode. The use of wires for MIG welding have increased between 80 and 95%.
This type of welding is a versatile process, being able to deposit the metal at a great speed and in all positions. It is used in small and medium thicknesses in steel structures. Also in aluminum alloys where a high welding resistance is needed. The metal tubular electrode used in MIG welding serves as a filler for welding. The electrode is consumed during the welding of the parts.