MIG Vs. TIG Welders
Metal inert gas (MIG) welding and tungsten inert gas (TIG) welding are both techniques that use a gas to shield the weld puddle from the atmosphere. The atmosphere contains gases that can cause defects to the weld, including nitrogen, oxygen and hydrogen. Carbon dioxide, which is not an inert gas, is sometimes used to shield the weld puddle, so more precise but less established terms are gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW). Does this Spark an idea?
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History
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Both MIG and TIG welding techniques were developed in the early 1940s in response to the demands of weapon production. TIG was developed for the aircraft industry because the clean, strong joints it provides are ideal for aircraft fabrication. MIG was developed to improve the speed of weapons production. Both techniques quickly found a place in manufacturing during the postwar economic boom.
MIG Welding Method
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TIG welding uses a Noncombustible tungsten electrode. MIG welding uses a machine-fed spool of solid steel wire that passes through a liner and out to the MIG gun's contact tip. The hot contact tip melts the wire and the weld puddle is formed. The shielding gas, most commonly an argon mixture, then flows from the MIG gun to protect the weld from the atmosphere. The increase in efficiency over using flux-coated welding rods is obvious, and because it is easy to learn, training costs are low.
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TIG Welding Method
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TIG welding uses a noncombustible tungsten electrode and an electric current to produce an electric arc between the electrode and the base metal. The heat from the arc produces the weld pool by melting the base metal itself. A filler wire or rod can be used to add any needed metal to the puddle, and the shielding gas, most commonly an argon mixture, flows out of the torch through a heat-resistant ceramic nozzle. High-amperage application may require a water-cooled TIG machine.
Benefits of MIG Welding
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Longer welds without stops and starts increase productivity and produce a smoother weld. It is an ideal technique for use with robotic welders, such as those on many assembly lines. Its inexpensive machines and easy-to-learn technique make it a popular choice for home use. The welder can weld from any position, and there is almost no cleanup required. It has a higher deposition rate, or the rate at which metal is deposited on the weld.
Benefits of TIG Welding
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The TIG technique produces superior-quality welds. The welder has precise control of the heat of the electrode, and better heat control results in fewer distortions. There is little or no spatter, which is little droplets of molten metal generated at the welding arc. Welds can be made with or without filler metal since the melted base metal itself forms the weld, and it can be used to weld more metals and alloys than any other process.
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References
Resources
- Photo Credit welder at work6 image by Carbonbrain from Fotolia.com mig welder image by Jake Hellbach from Fotolia.com
