Observation of arc phenomena in plasma GMA welding process

This paper presents characteristics of ionized gas metal arc processing which consists of a torch, a welding wire, shielding gases and two power sources. One of power sources ionizes the shielding gases before feeding into the arc region and another stably produces the arc with melting wire electrode. The degree of ionization in the shielding gas is well regulated by the primary power source, and then the secondary power source is able to control the arc devotedly, including the production and detachment of molten droplet at tip of the wire electrode. It is concluded that the ionized gas metal arc can make a stable processing of welding without spatters and fumes in comparison with the conventional gas metal arc processing. Furthermore, it is suggested that the ionized gas metal arc is very useful for not only welding but also thermal spraying for producing a fine coating of metal surface.