This article discusses about the topic mig vs arc welding. Welding is a fabrication technique in which two or more metals are joined together with the help of heat and pressure.
Different sources of heat provide different amount of heat at the joint. Different amount of heat and pressure will result in welds of different properties. In this article we shall focus on two kinds of welding namely mig welding and arc welding. Let us start our discussion with the definition of welding.
What is welding?
Welding is a fabrication technique used to join two or more metals. This is done with the help of heat and pressure. An optimum amount of both these parameters are needed to provide the weld of desired properties.
If any one of the parameters is not properly regulated then the weld formation will not take place properly and the weld may break due to weakness. Different applications require different types of weld properties, so the sources of heat may be changes in order to make the welding process economical and energy saving.
What is mig welding ?
Mig welding stands for Metal inert gas welding. As the name suggests, this type of welding includes the participation of inert gas like Helium.
Helium protects the weld pool and the bare wire electrode. The welding takes place as a result of arc striking the surface of the work piece. The tip of the electrode is the place where arc takes place. The arc generates enough heat to create a weld pool in the surrounding area. A weld bead is formed which is allowed to cool at room temperature. This weld bead is the desired joint.
Image credits : Weldscientist, RK WL GMAW, CC BY-SA 4.0
What is Arc welding?
Arc welding as the name suggests uses an arc to fulfil the purpose of welding. The arc is generated by an AC or DC supply. A consumable or non consumable electrode can be used in this process.
There are four types of arc welding which are been discussed in the later section of this article. The heat generated from the arc is used to join the two metals. An arc is formed when there is high voltage passing through the electrode and the electrode is lifted by a very small distance from the work piece disconnecting the circuit. The arc flows through this short distance.
Mig vs arc welding strength
The strength of welds are different for different welding processes. The table below shows the difference between mig welding and arc welding strength.
| Mig welding | Arc welding |
| The welding is stronger on thinner materials | The welding is weaker for thinner materials |
| The welding is weaker on thick materials | The welding is stronger for thick materials |
Gasless mig vs arc welding
The comparison between gasless mig vs arc welding is given in the table below
| Gasless mig welding | Arc welding |
| No gas is required for shielding | No shielding is required |
| Better for both thin and thick sheets of metals | Better for thick sheets for metals |
| The set up is expensive | The set up is cheaper than gasless mig |
Submerged arc welding vs mig welding
The comparison between submerged arc welding and metal inert gas welding is shown in the table below
| Submerged Arc welding | Mig welding |
| Uses continuous feed wire | Uses continuous feed wire |
| Uses powdered flux for shielding | Uses inert gases like Helium for shielding |
| Fully automatic | Semi automatic |
| Used for only down handing welding | It can be used in various positions |
| Used for very thick metals | Used for thin plates. |
Spray arc welding vs mig
| Spray arc welding | Mig welding |
| Molten metal droplets are transferred through the arc | Only electric spark is passed through the gap between electrode and the surface of workpiece |
| Used for thicker metals or butt joints | Used for thin metal sheets |
Shielded metal arc welding vs mig
| Shielded metal arc welding | Mig welding |
| Conventional arc welding process which uses a flux to shield the weld. | A continuous wire is fed to the work piece. A spark between the tip of the wire and workpiece melts the wire and makes a weld pool |
| Manually operated | Semi automatic |
| The coating of the electrodes evaporates that acts as shielding gas | Inert gases like Helium is used for shielding |
Mig welding vs electric arc welding
| Mig welding | Electric arc welding |
| Continuous wire is fed to the work piece | A stick electrode is used for welding process |
| Works on thinner materials | Works on thicker materials |
| Uses inert gases for shielding | Uses the evaporated electrode coating for shielding purposes. |
Is arc welding better than mig?
The answer to this question depends upon the type of application required. Both of these welding techniques are good for their respective application requirements.
If we want to weld thinner metals than mig welding is suitable as it gives a good finish for thin sheets of metals. When the metal is thick than a good weld will be formed when we use arc welding. Mig is not as effective on thicker metals as arc welding.
Sources of heat in welding
The following list shows the sources of heat in welding processes
- Arc– Arc is formed when a high amount of voltage is passed through the electrode when it is in contact with the work piece. The electrode is lifted by a very small amount such that a small gap is created. Due to high voltage the electrons jump from the electrode to the surface of the work piece. This is called as an electric arc.
- Plasma– Plasma is nothing but an electrically charged gas. This electrically charged gas particles produce enough heat on the surface of work piece that it can be used for welding
- Torch– A torch is simply a flame throwing device with a nozzle through which flame comes out. The high temperature flame is directed towards the area where welding needs to be done.
- Laser– The energy from lasers heat up the surface of work piece. The lasers produce a very high temperature at the surface of the work piece.
- Electron beam– Electron beams can be directed to the work piece to provide heat energy at the surface. The electron beam is converged to a single point using deflecting apparatus.
Hi ….I am Abhishek Khambhata, have pursued B. Tech in Mechanical Engineering. Throughout four years of my engineering, I have designed and flown unmanned aerial vehicles. My forte is fluid mechanics and thermal engineering. My fourth-year project was based on the performance enhancement of unmanned aerial vehicles using solar technology. I would like to connect with like-minded people.