Metal Inert Gas Welding (MIG)
MIG welding was developed in the 1940's and 60 years later the general principle is still very much the same. MIG welding uses an arc of electricity to create a short circuit between a continuously fed anode (+ the wire-fed welding gun) and a cathode ( - the metal being welded).
The heat produced by the short circuit, along with a non-reactive (hence inert) gas locally melts the metal and allows them to mix together. Once the heat is removed, the metal begins to cool and solidify, and forms a new piece of fused metal.
A few years ago the full name - Metal Inert Gas (MIG) welding was changed to Gas Metal Arc Welding (GMAW) but if you call it that most people won't know what the heck your talking about - the name MIG welding has certainly stuck.
MIG welding is useful because you can use it to weld many different types of metals: carbon steel, stainless steel, aluminum, magnesium, copper, nickel, silicon bronze and other alloys.
Here are some advantages to MIG welding:
The ability to join a wide range of metals and thicknesses
All-position welding capability
A good weld bead
A minimum of weld splatter
Easy to learn
Here are some disadvantages of MIG welding:
MIG welding can only be used on thin to medium thick metals
The use of an inert gas makes this type of welding less portable than arc welding which requires no external source of shielding gas
Produces a somewhat sloppier and less controlled weld as compared to TIG (Tungsten Inert Gas Welding)
