Laser-arc hybrid welding is noted as a promising joining process since it can compensate for the drawbacks or weaknesses in laser welding and arc welding by utilizing both features. Laser welding has gained great popularity as promising joining technology with high quality, high precision, high performance, high speed, good flexibility and low deformation or distortion, in addition to the recognition of easy and wide applications owing to congeniality with a robot, reduced man-power, full automation, systematization, production lines, etc. The defects or drawbacks of lasers and their welding are high costs of laser apparatuses, difficult melting of highly reflective of highly thermal-conductive metals, small gap tolerance and easy formation of welding defects such as porosity in deeply penetrated weld fusion zones. Arc welding is most widely used in joining applications because the machines are cheap and easy in operation, and the welding processes are highly stable and effective. The drawbacks are shallow penetration of weld beads in most cases, slower welding speeds, easier formation of humping weld beads at high speed welding, etc.
On the other hand, hybrid welding CO2, YAG, diode, disk or fiber laser and TIG, MIG, MAG, plasma or another arc heat source has been receiving considerable attention because it can achieve many advantages such as deeper penetration, higher welding speeds, wider gap tolerance, better weld bead surface appearance and reduced welding defects leading to a smaller amount of porosity in addition to complements of the drawbacks of both individual processes.
However, to be able to fully exploit the potential benefits arising from the combination of an arc and a laser beam in a hybrid welding process, a wide variety of parameters have to be understood and optimized. The main parameters significantly influencing the process result can be grouped in process parameters, material parameters and design parameters. The main parameters of the combined process are welding speed, process gas and the relative spatial arrangement of the two sub-processes. The sub-process arc welding is mostly governed by the arc parameters, in particular by the arc type. Moreover, wire diameter, wire stick-out and torch angle relative to sheet surface are relevant.
Considering the effect of the parameters of the sub-process arc welding, in this study, work on the effect of arc mode and arc power is reported. MIG welding is carried out with each parameter such as welding mode, arc current, arc voltage. The power of the arc has a significant influence on process stability and bead formation.