GMAW Subtypes
Gas metal arc welding (GMAW) is one of the most common arc welding methods used in industrial manufacturing. This welding method uses an electric arc, a consumable wire electrode, and shielding gas. GMAW processes are typically categorized into two subtypes, MIG and MAG welding.
GMAW is popular due to its speed, versatility, and ease of automation with industrial robots. Manual GMAW processes can be easily converted to robotic ones. For automation welding robots are integrated with a power supply, wire feeder, and welding torch. Integrating the FANUC Arcmate 120ic with the Lincoln Powerwave R500 power supply and torch allows for robotic automation of GMAW applications. Both subtypes of GMAW can be automated with arc welding robots. GMAW robots can always be used to switch between both subtypes by changing the type of shielding gas allowing for greater welding flexibility.
Robotic MIG
Robotic metal inert gas welding (MIG) involves the use of an inert shielding gas. Common inert gases used include nitrogen, argon, helium, or a mixture of those gases. Robots automating a MIG application will be able to weld non-ferrous metals. The Motoman MA1440 can weld aluminum or copper workpieces using the MIG welding method.The advantage of robotic MIG welding is that it preserves the purity of metals. Inert gas does not breakdown in high heat, preventing the chemical elements of the gas from infiltrating the weld pool. For welds in which purity is a concern, using the FANUC Arcmate 100ic or a similar articulated robot for MIG welding would be best.
Disadvantages of MIG welding include higher setup and maintenance costs. The use of shielding gas requires a stable environment. In addition, inert gas tends to be on the expensive side and since it is a consumable it will need to be routinely replaced. However, the speed, precision, and efficiency of robotic MIG applications can significantly increase productivity allowing for increased revenues to combat the costs of maintaining the robotic welding system.
Robotic MAG
Robotic metal active gas welding uses an active gas to shield the weld pool. These include carbon dioxide and oxygen. MAG welding robots may also use a combination of active gases or a combination of active and inert gases for the shielding gas. For instance, the ABB 1600 performing MAG welding may use a mixture of oxygen and carbon dioxide or a mixture of oxygen and argon. Robotic MAG welding is used for ferrous metals which include carbon steel, stainless steel, and iron. This is why GMAW is considered to be one of the most versatile welding processes since the MIG subtype welds non-ferrous metals and the MAG subtype welds ferrous metals, coving all types of metals. If the Motoman MA3100 is used to weld steel workpieces, but an aluminum workpiece needs to be welded, changing the type of shielding gas converts the MA3100 from a MAG welding robot to a MIG robot.The main advantage of robotic MAG welding is its cost-effectiveness. Active gases are inexpensive, helping to reduce setup and maintenance costs. The main disadvantage of MAG welding is active shielding gas can breakdown in high heat, potentially altering the chemical composition of the weld.