Hrbrid Laser-Arc Welding

Hybrid Laser-Arc Welding 5 solved satisfactorily by the laser welding process alone, e.g., joining of tailored blanks in the automotive engineering; welding of heavy plates in shipbuilding industry; as well as high speed welding of crack-susceptible materials.In searching for suitable solutions, the hybrid laser welding was developed into a viable joining technique with significant industrial acceptance during the last decade.According to the combination of various heating sources used, hybrid welding can be generally categorized as: (1) laser-gas tungsten arc (GTA) welding; (2) laser-gas metal arc (GMA) welding; and (3) laser-plasma welding 25 .Since laser welding offers deep penetration, primary heating sources commonly used in hybrid welding are CO2, Nd:YAG, and fiber lasers.The first two types of lasers are well established in practice and used for various hybrid welding process developments.While the fiber laser is still in development for industrial applications, it seems to be a future primary heating source for hybrid welding due to its high beam quality.The secondary heating sources used in hybrid welding are mainly electric arcs.Dedicated processes can be divided into GMA welding with consumable electrodes and GTA welding with non-consumable tungsten electrodes.In GMA welding, the arc is burning between a mechanically supplied wire electrode and the workpiece.The shielding gas used in GMA welding was found to have significant effects on arc shape and metal transfer 38,39 .Hence, GMA welding can be subdivided into metal inert-gas (MIG) and metal active-gas (MAG) welding according to the type of shielding gas used.In GTA welding, a chemically inert gas, such as argon or helium, is often used.A special form of this is the plasma arc welding (PAW), which produces a squeezed arc due to a special torch design and results in a more concentrated arc spot.