Plasma welding represents an advanced process within the extensive category of arc welding processes. Here, the arc is generated between the workpiece to be processed and a special electrode. Similar to TIG welding, the arc is created between an electrode made of water-cooled tungsten and a precision nozzle. In addition to this main arc, another arc, known as a pilot arc, burns between the electrode and the nozzle with an adjustable current of 3 to 30 A. During the welding process, special plasma gas, usually in the form of argon, is fed between these two components. The pilot arc creates an ionized trail, which is a prerequisite for the arc distance. This enables reliable and highly precise ignition of the main arc without the need for high-frequency applications.
A notable feature of plasma welding is the characteristic constricted arc. This special effect is achieved through a combination of different physical mechanisms. Compared to other welding processes, the restricted plasma arc has a significantly higher energy density and reduced beam divergence. The molten pool that forms during welding is protected by a shielding gas environment. This shielding gas is often pure argon or a mixture of gases with a high proportion of argon. This can be combined with hydrogen or helium to achieve the desired properties.
The significant advantage of plasma welding lies in its extraordinary stability and the precise shaping of the arc column. In contrast to TIG welding, where the diameter of the arc increases significantly with increasing distance, the plasma arc remains remarkably constant from the electrode tip to the workpiece diameter. This property results in narrow seam widths and enables extremely precise welding results to be achieved. Plasma welding is used in a wide range of industries, including aerospace, automotive, and metalworking. HORN's expertise and implementation skills enable the creation of sophisticated welded joints of the highest quality.
