Effect of applying electrical potential to a CO2 laser welding of different thickness plates

This study was aimed at developing laser welding with an applied voltage potential to increase the bead root width in laser welding. Also, in order to enhance the welding speed and the butt joint gap tolerance, the influences of the experimental conditions: supplied voltage between plate and backside electrode, welding speed, plasma operate gaseous species, and the butt joint gap, on the bead root width were investigated. Although it is necessary to avoid over heating and melting the plates, it is applicable for higher speed and wider gap butt joint welding than a conventional laser welding. In the case of butt joint welding with a thickness of 2.0 and 0.8 mm steel sheets by using 5 kW CO2 laser system, it is concluded that this method is effective for increasing of the welding speed from 5 to 8 m/min. Knowledge of optimum conditions and configurations has guided to extend this process to more challenging structural materials such as a tailored blank steel sheet.