Which component of MIG welding supplies the heat needed to melt the base and filler materials?

The welding machine is the component responsible for supplying the heat necessary to melt both the base material and the filler material during MIG welding. It generates the required electrical arc that creates extreme temperatures, allowing the metals to fuse together effectively.

This process involves the transformation of electrical energy into heat through the resistance of the welding circuit, typically by creating an arc between the electrode and the workpiece. The arc melts the edges of the base material and the wire electrode, which acts as the filler material, creating a weld pool that solidifies upon cooling to form a strong bond.

In contrast, the wire feeder's role is to continuously supply the filler wire to the weld joint, ensuring a steady feeding of material into the weld. The electrode itself is the filler material that is melted and deposited into the weld, but it does not generate the heat itself. The gas nozzle is primarily responsible for directing the shielding gas around the weld area, protecting it from contamination. Thus, the specific function of heat generation is distinctly fulfilled by the welding machine.