Understanding metal inert gas welding (MIG)

Today I will be discussing the definition, applications, diagram, equipment, working, advantages, and disadvantages of metal inert gas (MIG) welding. Previously, some article was published on arc welding. checkout below;

Metal inert gas welding (MIG)


What is metal inert gas (MIG) welding?

MIG welding is an arc welding process, which is shielded by an external gas welding (argon, helium, co2, argon + oxygen, or other gas mixture.) It uses consumable electrode wire, which has a chemical composition similar to the parent material. This process is semi-automatic due to the automatic feeding of the filling wire electrode. The operator only controls the torch positioning and the welding speed.

MIG welding is also known as gas metal arc welding (GMAW), which uses a continuously fed solid wire electrode. It melts the base materials together, which solidifies and produces bonds using the welding gun. The welding gun also feeds an inert shielding gas alongside a wire electrode. This helps to protect the process from airborne contaminants.

Read more: Understanding submerged arc welding

MIG welding was first originated in the USA in 1949 for welding aluminum. It became popular around 1952 in the UK for welding aluminum using argon as the shielding gas, and carbon steels using co2.co2 and argon-co2 mixtures. It is also known as a metal active gas process (MAG).

MIG welding equipment

MIG welding equipment includes:

MIG welding equipment

  • Consumable electrode
  • Inert gas supply
  • Welding bead
  • AC or DC power supply. And
  • Electrode feeding mechanism

The addition of shielding gas from the arc to the weld pool has importance, which includes:

  • Stabilization of the arc roots on the material surface
  • Forms the arc plasma
  • Ensures smooth transfer of molten metal droplets from the wire to the weld pool.

Read more: Understanding shielded arc welding (SMAW)

Diagram of MIG welding:

diagram of metal inert gas welding

Watch the video below to learn the working of MIG welding:


The followings are applications of MIG welding:

The gases are normally used on steel; co2 argon + 2 to 5% oxygen and argon +5 to 2% co2 and nonferrous metals like aluminum, copper or nickel alloys, argon, argon/helium.

Read more: Understanding plasma arc welding

Advantages and disadvantages of MIG welding


below are the advantages of metal inert gas (MIG) welding in their various applications.

  • It is easy and simple
  • A filler material is not needed
  • The gas is protected automatically
  • A continuous electrode is easy to feed
  • It does not produce slag


Despite the great benefits of MIG welding, the following are disadvantages of the process.

  • The welder is exposed to hazardous gases
  • Weld becomes porous if the welding gun is not properly handled
  • Improper welding may lead to the floating of solid impurities over the liquid welding
  • It is expensive and the equipment is not portable
  • It cannot be done outdoor because of the effect of wind, dispersing the shielding gas

Read more: Understanding Arc stud welding

That is all for this article, Where the definition, applications, diagram, equipment, working, advantages, and disadvantages of metal inert gas (MIG) welding are being discussed. I hope you get a lot from the reading, if so, kindly share with other students. Thanks for reading, see you next time!


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