Argon is the most widely used gas for welding applications, and welders frequently use this gas in tandem with another gas. Oxygen, helium and carbon dioxide are some of the most widely used gases to combine with argon. The exact gas combinations used depend on the application.
The gas combination used for welding can have a great effect on the metal it is applied to. The right choice of gas depends heavily on the metal that will receive the weld. The gas combination used to weld a specific metal affects the weld's appearance, weld quality and smoothness of operation.
In terms of cleaning action, argon performs better than other gases. Argon will shield the weld from contamination and reduces spatter. When welders use argon gas for welding, the welding arcs are more stable. Oxygen and helium improve welding penetration patterns when combined with argon.