Argon is used as a shielding gas for welding applications.
Argon is a colorless, odorless, tasteless, non-toxic gas. Heavier than air, it has a low thermal conductivity. It is considered an inert gas. Argon's unique properties make it a good choice when a gas is needed as a protective layer in certain industrial uses, including some welding applications.
Shielding
Argon is heavier than air, so it can create a blanket or pocket around an object to shield it. This allows a smooth transfer from the weld wire to the molten weld pool without disruption. This keeps out impurities from the weld, helping to increase the stability of the finished product. It also allows for a slower flow of the welding, which means a cleaner, more solid weld.
Stabilization
The protective shield argon forms stabilizes the arc from the welding tool to the metal or weld pool. It is a nonreactive gas, which means it stays mostly inert during the weld process. The pocket it forms around the arc allows the arc and the metal to have clear contact. It also keeps it stable and connected during the weld. Argon's conductivity assists in the transfer of the arc energy to the metal. The flow of the gas thru the welder keeps a constant pocket around the weld pool and the arc, and also stabilizes the transfer.
Argon Mix
Argon is used alone during the welding process, primarily for aluminum welding. It is often paired with another gas to increase and enhance certain properties in other types of welding. Argon and carbon dioxide is a common mix, as carbon dioxide is a good gas to transfer energy from the arc to the weld puddle. Argon and helium are used for a variety of metals, and oxygen is added to Argon in some mixes for some applications. The mix will depend on the type of metal and weld and often the preference of the welder using the gas.
