MIG welding is used to join aluminum and metals that are non-ferrous. The technology was invented back in the 1940s and has significantly evolved ever since. The MIG welders now have a wide variety of features that make them quite useful and suitable for a broad range of uses, including steel welding. MIG welding is a semi-automatic process which makes use of inert gases and a feeding wire from a welding gun. Some of the top features to look for if you need to find the best MIG welder are highlighted below.
A typical MIG welding gun has a control switch, power cable, contact tip, gas nozzle, gas hose, and electrode conduit. When the operator presses the trigger or control switch, a wire feed is initiated and the shielding gas and power flow to cause an electric arc to occur. The contact tip is connected to the power source of the welding unit through a cable. It transmits and directs electrical energy to the welding area. The feed wire is guided and protected by the electrode conduit, which prevents buckling as well as maintains constant feed of the rod. The inert gas is directed to the welding zone by the nozzle.
The electrode holder that is most commonly used is a semi-automatic holder that is cooled by compressed air that circulates through it. This type of holder is used for welding that requires lower levels of current. The other common type of electrode holder is the semi-automatic water-cooled electrode. It is similar to the air-cooled electrode except for the fact that water is used to cool it instead of air. It is suitable for welding jobs that require higher current levels.
A majority of the MIG welders use a power supply that has a constant voltage. The length of the arc is usually dependent on the voltage. This means that any small changes in the arc length can result in significant changes in current and heat input. A shorter arc, for example, will result in higher heat input that causes the electrode to melt faster. This, in turn, restores the original arc length. Constant voltage, therefore, means that the arch length remains consistent. A similar effect is sometimes achieved using a power source that has constant current.
The electrode, also called MIG wire, is a metallic alloy. The size and alloy of the electrode are mainly determined by the composition of the metals that are to be welded, the joint design, and the condition of the surface of the material.