Robotic GMAW vs Robotic Plasma Welding
GMAW and plasma welding are two types of fast arc welding processes that yield high-quality welds. While they both produce similar outcomes, they are not interchangeable with one another as their methods have some key differences.
Robotic GMAWRobotic GMAW stand for gas metal arc welding and is also referred to as robotic MIG, metal inert gas welding. GMAW is one of the most common robotic arc welding methods since it automates easily with industrial robots. The FANUC Arcmate 120ic is often deployed in the automotive industry for GMAW applications.
Robotic GMAW applications require the integration of an arc welding robot, welding torch, robotic welding supply, and wire feeder. During welding a consumable wire electrode is continuously fed to the robot’s torch. The articulated robot will apply the torch to the workpiece, aligning the wire in-between the metals and electric arc. The wire electrode serves as the filler material that will be melted by the arc and cause the joining of the metals when it solidifies. A shielding gas is used to protect the weld pool.
GMAW robots are ideal for welding thick metals such as steel and aluminum. The filler wire speeds up weld time and makes for a more efficient process for thick metal welding. Weld times are also sped up since GMAW robots only need a single pass of the torch to join metals together.
Robotic Plasma WeldingPlasma arc welding is often viewed as similar to automated TIG welding since it also uses tungsten electrodes. Automating PAW with industrial robots simplifies the complexity of the application and improves the accuracy and quality of welds. The Motoman MA1400 and the FANUC Arcmate 100ic are two examples of six axis robots that can perform plasma welding. When automated with industrial robots, a plasma cutter and power source will be needed for robotic PAW.
The PAW process involves heating an inert gas to convert it to plasma. The tungsten electrode is suspended inside the torch, separating the arc and shielding gas allowing the plasma to flow out. When the factory robot applies the torch to the metal workpieces, the plasma melts and joins them together.
PAW robots can be used to weld a variety of metals, regardless of thickness. Robotic plasma welding is known for its short cycle times and precise welds due to the high temperatures and small heat affected zone. Both narrow and deep welds can be achieved with plasma welding robots without part distortion.
Key DifferencesFrom the descriptions of each process above, one can see their methods are quite different as one uses a wire electrode and the other uses plasma to produce welds. GMAW robots are integrated with traditional welding torches, while PAW robots use plasma cutters as their EOAT. The same plasma cutter can be used for automated plasma cutting applications, for additional flexibility. A ABB 2400/16 can complete both plasma welding and plasma cutting without having to change end-effectors. Most used FANUC welding robots for sale include a GMAW power supply, such as the Lincoln Powerwave 455M.
Robotic plasma welding is more versatile of the two since it can be used for both thin and thick metals, while GMAW is best for thicker weldments or large workpieces. Those who only need to weld thick metals would benefit the most from a GMAW robot since the filler metal allows for faster cycle times. Those needing to weld a variety of workpieces with varying thicknesses would be better with a plasma welding robot. PAW does not use filler metal allowing for clean welds of thinner metals. The high heat of the plasma allows PAW robots to be capable of welding thick metals too.