Quality Monitoring of Laser Welding

In this paper, a study of quality monitoring technology for the laser welding was conducted. The laser welding and the industrial robotic systems were used with robot-based laser welding systems. Over the past years, Trumpf's 4kW Nd:YAG laser (HL4006D) and ABB's IRB6400R robot system (payload:120kg) were used. The new laser source, robot and laser scanner system are used to increase the processing speed and to improve the efficiency of processes. The laser system used in this study was IPG's 1.6kW Fiber laser (YLR-1600), while the robot system was Hyundai Heavy Industry's HX130-02 (payload : 130kg). The robot-based laser welding system was equipped with a laser scanner system for remote laser welding. The welding joints of steel plate and steel plate coated with zinc were butt and lapped joints. The quality testing of the laser welding was conducted by observing the shape of the beads on the plate and the cross-section of the welded parts, analyzing the results of mechanical tension test, and monitoring the plasma intensity by using UV and IR sensor. This paper proposes the quality monitoring method and the robot-based remote laser welding system as a means of resolving the limited welding speed and accuracy of conventional laser welding systems.