mig welding techniques also called as gas metal arc welding. The shield gases, helium, argon, carbon-dioxide are mixture during welding process. In this process the power source (DC power) connected to thin bare metal wire electrode and the work piece. The torch used in this process, when the torch carries a shielding gas hose, current carried on conductor and solid wire electrode the wire electrode is connect to positive pole of power source.
Now the arc is generated between the work piece and electrode where the welding pool is created, that is melt the both work piece and electrode. In this process the wire electrode fed from a spool through the torch (welding gun) at a constant speed.
In this mig welding techniques, the diameter of the wire may be as from 0.1 mm to 3.2 mm, which the wire is feed through the contact tube of gun.
When the process DC current is used and give deeper penetration and possible for thicker work piece the shield gas passed through the hose.
Shield gas used in mig welding techniques:
It is 38% heavier than air, which is possible for flat and horizontal fillet weld and pure argon used in all metals.
It is lighter than air so that reason high amount of gas used in welding. It is used to aluminum, magnesium and copper metal can be welded.
Carbon dioxide (co2):
That is used in welding of steel
Argon oxygen mixture, helium argon carbon dioxide mixture, argon carbon dioxide mixtures are used in this process.
Advantages of mig welding techniques:
- high welding speed
- it have less distortion and there is no slag removal
- no flue
- multi-layer can be welded
- it is easily automated
Disadvantages of mig welding techniques:
spatter is high so deposition efficiency will be low
- All thickness of steels made weld
- Stainless steal
- Copper and its alloy
- Magnesium alloy
- Heat resisting alloys
- Carbon and low alloy steel
- Magnesium alloy