New aspects of monitoring with a CMOS camera for laser materials processing

Abstract

A new system for process monitoring of laser beam welding based on a CMOS-camera was presented in former presentations [1,2]. The system observes the welding process online and coaxial to the laser beam. Until now we have got various experiences with this system in industrial applications and experimental trials. For example the system yields interesting results for cutting processes with regard to incomplete cut and development of dross. Another application will show the availability of the system for welding in the automotive industry. One of the most interesting processes in this industry is the welding of zinc coated steel sheet in an overlapped joint configuration. Due to the low evaporation temperature of zinc, it is necessary to weld this material with a defined gap between the two plates. Recorded films are analyzed and some effects as a consequence of different gap widths are presented in the films. The films and the resulting curves show the possibility to monitor certain weld failures, caused by different gaps in between the joint.