Plasma welding is a type of welding that uses an electrical arc to superheat gases and create a stream of plasma that is incredibly hot and highly concentrated within a small area. Most plasma welders utilize a single type of gas, often argon, to take the arc and transmit the heat, while also using a second gas, often called a shielding gas, to keep the plasma focused in a single small space by preventing heat from distributing outside the intended area. Plasma welding is commonly used in the aerospace industry, in applications such as automotive and pipeline construction, and even for manufacturing commercial quality kitchen products.
First introduced in the 1960s, plasma welding was intended to replace other types of welding, such as gas tungsten arc welding (GTAW). Sometimes also referred to as plasma arc welding (PAW), plasma welding uses a welder that uses several sources of gas to produce a powerful, precise source of heat for welding. The basic design of a plasma welder uses a hand-held welder and torch head connected to a larger control console. This console allows the user to adjust various aspects of the welder and to ensure that the system remains properly cooled during use.
A plasma welder will usually have a fairly narrow nozzle at the end of the torch head, and an electrode, usually tungsten, located up inside the nozzle. This protects the electrode from damage from coming into contact with other materials. The nozzle can also be made somewhat adjustable to allow the user to control the size of the plasma stream. Plasma welding is performed by creating a stream of plasma, or superheated gas, which carries an arc from the electrode down to the material being welded. The shielding gas is released around the plasma to keep the stream narrowly focused and to prevent more heat loss than GTAW types of welders.
Plasma welding uses plasma to create tremendous heat in a very small area, allowing for much finer welds than many other types of welding. This precision allows plasma welding to be used on everything from commercial kitchen equipment, to airplane repair, and even assembling surgical equipment. The incredible heat from plasma welders is typically so intense that most welders are water cooled to ensure the torch head and handle do not begin to melt from within. Plasma is also used in a number of other commercial applications such as plasma cutters, which use jets of plasma to cut through metals quickly and precisely.