What is Plasma Arc Welding (PAW) in Welding?

Plasma arc welding (PAW) is an arc welding process that uses a constricted arc between a non-consumable electrode and the weld pool (transferred arc) or between the electrode and the constricting nozzle (non-transferred arc). Shielding is obtained from the ionized gas issuing from the torch.

The constricted arc forms when the gas flow through the nozzle is sufficient to ionize the gas and create a plasma. The plasma is electrically conductive and provides a low impedance path for the arc current.

The process can be used with a variety of metals, but it is most commonly used with stainless steel and aluminum. PAW is often used for welding thin materials, welding in difficult-to-reach places, and for welding under high heat input conditions.

The process is somewhat similar to gas tungsten arc welding (GTAW), but the plasma arc is narrower and hotter, and the gas flow is much higher. This results in a faster welding speed and greater penetration.

Plasma arc welding can be performed manually or automated. When performed manually, the process is similar to GTAW, with the operator holding the torch and electrode in one hand and feeding the filler metal into the weld pool with the other hand. When performed automatically, the process is similar to gas metal arc welding (GMAW), with the torch and electrode mounted on a robotic arm and the filler metal fed from a spool.

Which electrode is used in PAW?

Plasma arc welding can be performed with a variety of electrodes, but the most common is the tungsten electrode. Tungsten is a very strong and heat-resistant material that can withstand the high temperatures of the plasma arc.

What is the temperature of plasma for PAW?

The temperature of the plasma arc in plasma arc welding can be as high as 30,000 degrees Celsius (54,000 degrees Fahrenheit).

Plasma needle arc welder

A plasma needle arc welder is a type of plasma arc welding in which a needle-shaped electrode is used to create the arc. This allows for more precise welding, which is why this method is often used for delicate work such as welding electronic components.