TIG, MIG, and MAG versus laser welding

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What differentiates TIG, MIG, and MAG? What do they have in common, and what are the biggest differences compared with laser welding?

Some basic similarities and differences between TIG, MIG, and MAG

TIG, MIG, and MAG all involve welding using a short arc. Short-arc welding refers to the short arc between the welding wire and the material to be welded. The welding equipment creates such high voltage that an arc is formed between the wire and the material. The electrons of the arc are transferred to the material via the welding wire and heat it to a temperature at which it starts to melt. In MIG and MAG welding, the wire becomes so hot that it melts into the material. TIG welding, however, uses a tungsten electrode which does not melt.
Although both MIG and MAG use the same equipment as TIG welding, the gases used often have completely different purposes – metal inert gas (MIG) and metal active gas (MAG), i.e. a protective (non-reactive) gas and a gas that actively affects the material being welded. In all three welding methods, the power source of the welding unit is connected to the material to be welded. Voltage is generated by passing electricity out of the cabling/nozzle and holding it close to the material. An arc is then formed between the nozzle and the material.

What does TIG welding involve?

TIG stands for tungsten inert gas. Tungsten is actually a Swedish word that is used internationally (though paradoxically in Sweden the word “wolfram” is used when talking about this element). Protective (non-reactive) gas is supplied, either manually or automatically, to avoid the material being welded being affected by oxygen.

TIG welding is a method that is easy to work with, but due to the requirement of additives, the cost of welding tends to be high. In addition, the large amount of heat makes the material to be welded initially quite unstable, so it needs to be cooled before it can be processed. Furthermore, TIG welding is not exactly precise and often requires a lot of post-processing, grinding, and straightening.

What does MIG welding involve?

MIG stands for metal inert gas. The gas most commonly used in MIG welding is the noble gas argon, which is used to keep away the oxygen that affects the material being welded (through the oxidisation of iron and titanium, for example). The atoms of the molten material move rapidly and can easily react with other substances. The argon protects the molten material from oxygen until the material solidifies without affecting or reacting with the metal itself.

MIG and MAG are effective welding methods for large gaps and are common in many industries – not least those using very low-alloy steel – but often require a lot of post-processing in the form of grinding and straightening. Due to the powerful effect of the heat, the tolerances are not especially good.

What does MAG welding involve?

MAG stands for metal active gas. Although MIG and MAG require the same equipment, power source, and wire feeder, in MAG welding the gas needs to react with the material being welded. You may, for example, want to release something from an alloy or otherwise affect the material by adding one or more substances. Carbon dioxide is the gas most commonly used in MAG welding.

What are the advantages of laser welding compared with TIG, MIG, and MAG?

In most cases, laser welding can replace traditional welding, offering greater safety, precision, and speed, and usually at a fraction of the energy consumption required in TIG, MIG, or MAG. The speed of laser welding benefits productivity, and in practice this means that a single laser station can produce as much as several TIG, MIG, or MAG stations.

The costs of gas and wire disappear with laser welding, and much less energy needs to be transferred to the base material than in traditional welding. This in turn results in much less shrinkage at the joint, and thus less risk of deformation. In addition, fewer gases are released as laser welding heats less of the material.

Furthermore, laser welding is significantly safer for workshop staff than traditional welding methods are. TIG, MIG, or MAG welding pose a high risk of burns and heat radiation to operators due to their proximity to the welding process (which requires a constant temperature of at least 1,500 degrees Celsius).

Please contact me if you want to find out more about laser welding and how Permanova can help you develop a laser station that can further streamline your production. You can also find many more articles about lasers and laser welding on our website under “Inspiration”.

Björn Lekander | 2019-10-03