Industrial robots have become quite popular amongst manufacturers particularly when it comes to automating complex welding applications such as the case with plasma welding. Plasma arc welding, or PAW, is an arc welding process in which an electric arc heats inert gas to turn it into plasma that is then used as the energy source to melt and join workpieces together. PAW is similar to TIG welding in that they both use a tungsten electrode to form the electric arc and a shielding gas to protect the weld. However, they differ because with plasma welding the electrode is contained within the body of the torch keeping the plasma arc separate from the shielding gas. Automating plasma welding applications with robots such as the FANUC Arcmate 120ib provides tight, focused welds to increase product quality.
Plasma welding robots gained their popularity due to the precise, clean, and seamless welds they produce making them ideal to complete applications requiring high quality welds. Since the electric arc is contained within the torch it allows for precise targeting of the plasma. This prevents distortion of the workpiece unlike with TIG welding. Even though the plasma can reach temperatures of up to 30,000 degrees Fahrenheit, the constricted nozzle creates a small heat affected zone. This ensures only the welded area is impacted, protecting the integrity of the rest of the metal and producing clean, uniform welds consistently. The use of shielding gas such as argon, hydrogen, or helium further increases the quality of the weld by preventing atmospheric contamination which could lead to oxidation of the welded materials. The prevention of oxidation ensures strong, long-lasting welds are always achieved.
Plasma welding robots like the ABB IRB 4400/L30 are capable of welding thin and thick non-ferrous metals including steel, aluminum, magnesium, and copper to name a few. They are able to complete welds with only one pass, regardless of thickness due to the velocity and temperature of the plasma expelled from the weld torch. They can be easily programmed to maintain consistent control and temperature decreasing spatter errors that may result in the metals appearing porous or uneven. The reduction in errors means materials are not wasted and cycle time is decreased by not having to correct mistakes or start the weld completely over. Plasma welding robots complete the job accurately with one pass with every workpiece. The FANUC Arcmate 100ic has a repeatability of .08MM, meaning it has basically zero error. It is not feasible for a manual welder to match that level of repeatability.
Manufacturers are further drawn to plasma welding robots because they provide versatility which increases operation efficiency. Not only do plasma welding robots like the Yaskawa Motoman MH50-20 weld metals together, but they can also perform plasma cutting applications. When the flow of plasma is increased it allows the industrial robot to cut through metals instead of welding them together. By having one robot capable of completing multiple applications within a production process, operations become streamlined. With the integration of robots manufacturers also save on labor costs and the headache of trying to find highly skilled and qualified workers to complete plasma welding tasks.