INVESTIGATION ON Nd:YAG LASER-TIG HYBRID WELDING WITH FILLER WIRE

摘要

Laser-arc hybrid welding is considered one of the most promising joining technologies and has worldwide been elaborated for various applications in automobile, shipbuilding, and rail vehicle industries since 1980s. Compared to laser-MIG hybrid welding, laser-TIG hybrid welding with filler wire possesses the advantages of more stable process and higher weld quality. The basic objectives of this study are to optimize the experimental setup and understand the fundamental phenomena in laser-TIG hybrid welding with filler wire. For this purpose, a Nd:YAG laser with an output power of 2.5kW and a DC TIG welder were used in this experiment. Bead-on-plate welding was performed on low carbon steel. The influences of welding parameters on the weld depth, weld width and the process stability were analyzed. The results demonstrate that the introduction of a TIG arc to the laser welding process with filler wire can increase the welding efficiency and improve the weld formation. Among various parameters, the distance between the two heat sources has important influence on the weld profiles and welding with a helium arc can obtain a weld with deeper penetration and greater width than with an argon arc.