3. Addition products

Gas

The shielding gas used in the MIG/MAG process has two functions. The first, known as plasmagenic, is to ensure arc initiation and maintenance. The second is to protect the molten bath from the ambient air. The MIG process uses an inert gas (argon, helium or a mixture of the two). Argon-helium mixtures are commonly used in the assembly of light alloys. Helium increases process efficiency by raising arc voltage. It is particularly well-suited to the process, as it generates a hotter bath that favors outgassing and thus limits compactness defects.

The MAG variant uses a so-called active gas. It is composed of an argon base mixed with other gases in various proportions. These are mainly binary mixtures (Ar—O ₂ , Ar—CO ₂ ) or...