What is GMAW (MIG Welding) & How Does it Work?

Gas Metal Arc Welding (GMAW), commonly known as MIG (Metal Inert Gas) welding, is a welding process that uses a consumable wire electrode fed through a welding gun, which is connected to a power source and a shielding gas supply. The shielding gas protects the weld pool from contamination and oxidation, while the wire electrode melts and fuses the workpieces together.

Here is how GMAW (MIG welding) works:

Power source: The power source provides the electrical current necessary for the welding process. It can be a transformer, rectifier, or inverter that converts AC power to DC power.

Wire electrode: The wire electrode is fed through the welding gun at a controlled rate, typically using a spool or a drum. The wire electrode is made of a material that matches the base metal or filler metal being welded.

Shielding gas: The shielding gas protects the weld pool from atmospheric contamination and oxidation. Common shielding gases used in GMAW include argon, helium, or a mixture of the two.

Welding gun: The welding gun is held by the operator and contains the wire electrode, a contact tip, and the shielding gas nozzle.

Electrical arc: When the welding gun trigger is pulled, the power source creates an electrical arc between the wire electrode and the base metal, generating heat that melts the wire electrode and the base metal. The shielding gas flows through the nozzle to protect the weld pool from contamination.

Weld pool: The molten wire electrode and base metal combine to form a weld pool that cools and solidifies to form a welded joint.

MIG welding is known for its speed and efficiency, making it a popular choice for welding thin to medium gauge metal. It can be used to weld a variety of materials, including steel, stainless steel, aluminum, and copper alloys. MIG welding is commonly used in automotive, construction, and manufacturing industries.