Plasmahitsausta

Plasmahitsausta, or plasma welding, is a welding process that uses a plasma arc to heat and melt the workpiece, producing a weld. The method relies on a plasma arc formed by ionized gas passing through a constricted nozzle, which concentrates heat and increases energy density compared to conventional arc welding.

In typical plasma welding equipment, a tungsten electrode and a ceramic nozzle generate the plasma arc. Shielding gas, often argon or a mixture, protects the weld pool from the surrounding atmosphere. Some configurations also permit filler metal to be fed into the weld via a wire feeder. There are two main variants: transferred plasma arc welding, where the arc conducts through the workpiece, and non-transferred plasma arc welding, where the plasma arc stays within the torch and does not contact the workpiece. The process can be used in a spray or pulsed mode to control heat input and penetration.

Plasmahitsausta offers high energy density, which enables deep penetration and narrow welds, making it suitable for thin to medium-thickness sections in metals such as carbon and stainless steels, aluminum, and nickel-based alloys. It is valued for precise control, good weld quality, and relatively fast deposition rates in capable setups. Limitations include high equipment cost, the need for skilled operation and careful shielding gas management, and sensitivity to joint fit-up and material cleanliness.

Common applications are in aerospace, automotive, piping, and high-integrity welds where strong, precise joints are required. Safety considerations include UV exposure, thermal hazards, and fumes, necessitating proper ventilation and protective equipment.