The process by which metals are joined is known as welding. Welding helps to join metals or any other material at the molecular level. The process of welding comprises 4 components i.e. the metals, a filler material, a heat source and a shield from the air.
The welding process essentially is when a metal is heated to the melting point with some sort of shielding that protects it from the surrounding air. A filler metal is added to the portion that requires joining and a single metal piece is formed.
Types of Welding Processes
There are 4 most commonly used welding processes – shielded metal arc welding, flux core arc welding, metal gas inert welding and tungsten inert gas welding.
Shielded Metal Arc Welding
This welding process is also known as SMAW or stick welding and makes use of an electrode or rod that is powder coated. When heated, the powder coating melts and creates a shield from the air (oxygen). Sometimes, the electrodes have a filler metal that is added to the powder coating in order to hasten the welding process.
Metal Gas Inert Welding (MIG)
This process of welding is also known as Gas Metal Arc Welding (GMAW) or Metal Inert Gas Welding. In this process, a wire spool is used to feed wire to the joint. A gas contained in a bottle flows from the welding machine to the welding handle and protects the weld from the surrounding air.
Flux Core Arc Welding (FCAW)
FCAW makes use of the same machine as MIG welding. However, the difference is that both make use of only a wire with a flux in the centre or have a combination of the flux in the centre of the wire and make use of a shielded gas contained in a bottle.
Tungsten Inert Gas Welding
Also known as TIG, this welding process makes use of TIG, which is a torch that has a non-consumable electrode or rod made of tungsten, which has gas flowing through it. The tungsten electrode heats the metal. The filler metal is manually added whenever required. In TIG, the non-consumable electrode only produces heat in order to heat the metal and does not add to the welding filler material.
All the popular welding processes which are used these days work on basically the same principle. All of them need electricity in order to produce heat to weld the metals. However, the main difference between all the processes is the manner in which the filler metal is added to the weld and how it is shielded from the air.