When only the best weld quality will do, and welding speed is not an issue, then tungsten inert gas, or TIG,welding is a method that produces very good results. Welding bicycle and airplane parts are two examples of a situation where TIG welding is needed to create a weld that will not separate under any circumstances. Because it produces absolutely no surface ‘slag’ on the item being welded, this method can also be used for very exacting, delicate work, such as welding electronics into place. The bond it produces is both very clean and very strong, so applications such as pressure vessels and pipes can be TIG welded, but it is also suitable for small objects as well.
In TIG welding, a non-consumable tungsten electrode is used to provide the welding arc, with a separate piece of material to use as filler for the arc welding process when necessary.An inert gas that will not catch fire or explode when it is in contact with the welding arc’s intense heat typically a mix of argon and helium surrounds the welding arc to keep the air away from the weld, where oxygen could damage the bond before it has hardened. The presence of these gases means that welders using a TIG machine must be careful and wear proper protective equipment, however, because argon can destroy the human brain or lungs in cases of heavy exposure.
History and applications of TIG welding
TIG welding is an effective but painstaking procedure,so it must be carried out manually by someone experienced in this demanding skill.This is the reason that other welding methods are used for many applications, despite the all-round excellence of TIG welds.The technique was originally developed to be used in building aircraft during the 1930s and 1940s, when there was both a need for this type of welding to hold together materials that were going to be subjected to the massive stresses of flying,and when the gas shielding technology had become advanced enough to make TIG welding efficient. Pure helium was the initial gas used, giving the method its original name of “Heliarc,” but argon soon supplanted helium as the main ingredient, since it is cheaper and just as effective.
A TIG welding machine can be employed to weld nearly any weldable metal, although slightly different settings are needed for some types of metal.For most metals, the best power source for the electrode that heats and melts the filler metal is direct current (DC). However,aluminum welding sometimes requires the use of alternating current (AC) for best results, so a TIG welding machine able to power its electrode with alternating current is used in some applications.
TIG welding machines today
There are numerous TIG welding machines available to the modern welder, many of which include the latest welding technology and digital controls for maintaining a stable arc. Some of these welding machines are large and powerful, mounted on wheels and therefore best for workshop floor use, while others are compact designs that the welder can carry with them onto scaffolding or ladders thanks to their lightness and small dimensions.Modern TIG welding machines are also designed to operate over a large voltage range even a small, “micro TIG” can have a voltage range of 138 to 265 volts, meaning that it can be applied to welding everything from unalloyed to high alloy steel, cast aluminum, nickel alloy, copper, and the like.
Although originally designed for aircraft construction, the TIG welding machine has become a versatile, compact tool that is available for nearly every professional welding job imaginable, from aerospace applications to building computers to bicycle construction and repair.