Plasma Welding

Plasma arc welding is in many ways similar to gas tungsten arc welding, also known as tungsten inert gas welding (TIG). The difference is that in the plasma welding machine the electrode is positioned within the plasma torch. In this configuration, plasma is forced through a relatively small nozzle confining an electric arc, formed between the electrode and the workpiece, to a well-defined spot. The zone to be welded is heated by the electric arc and the plasma jet, which reaches high velocities approaching the speed of sound. Plasma arc welding is often faster and more accurate than gas tungsten arc welding.

Typical electric currents used in plasma arc welding range between 0.1 A to 300 A. Welding at currents lower than 25 A is often called microplasma welding. This mode can be used to weld wire meshes and metal sheets as thin as 10 micrometers. At the currents over 100 A, a powerful plasma jet, capable of penetrating through an entire workpiece forming a keyhole, is generated. Consequently, this high current plasma arc welding mode is termed keyhole welding. Keyhole welding can weld material up

to 1 cm thick in a single pass. Compared to gas tungsten arc welding, plasma arc welding offers greater energy concentration and better stability of the electric arc. It can also achieve greater arc lengths and offers better control of the arc. Just like plasma cutters, plasma welders can be integrated with CNC systems forming CNC plasma welding machines. Furthermore, both a plasma welder and plasma cutter can be part of a single multipurpose system.

Thanks to its versatility, plasma arc welding is used in a broad range of settings and applications including electronics manufacture, aerospace, marine industries, and medical device manufacture.