Metal inert gas welding (MIG)
Today I will be discussing on what is metal inert gas welding (MIG). Previously, some article was published on arc welding. checkout below;
- What is electric arc welding, its applications, advantages and disadvantages?
- Different types of electric arc welding process
- Safety precautions in arc welding operation
What is metal inert gas welding (MIG)?
Metal inert gas 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 have 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 on the torch positioning and the welding speed.
This 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 bond using the welding gun. The welding gun also feed an inert shielding gas alongside wire electrode. This help to protect the process from airborne contaminants.
MIG welding was first originated in USA in 1949 for welding aluminum. It became popular around 1952 in 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 metal active gas process (MAG).
MIG welding equipment include:
- Consumable electrode
- Inert gas supply
- Welding bead
- AC or DC power supply. And
- Electrode feeding mechanism
Addition of shielding gas from the arc to the weld pool have few importance, which include:
- 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
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.
Advantages of metal inert gas welding
- It is easy and simple
- Filler material is not needed
- The gas is protected automatically
- Continuous electrode is easy to feed
- It does not produce slag
Despites the great benefits of MIG welding, the following are disadvantages of this welding 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 effect of wind, dispersing the shielding gas
- Heat treatment of copper and copper alloys
- Heat Treatment of non ferrous metals
- Process of Heat treatment of ferrous metals
And that is it for this article, What is Metal inert gas welding (MIG). Its applications is also examined in this article. So, ask questions, comment and share. Thanks for reading!