Product Code: ICA10_205

Process Monitoring and Control during Hybrid Laser-Arc Welding of Medium Section Steel Sheets
Authors:
Wolfgang Fiedler, Fraunhofer Institute for Laser Technology ILT; Aachen Germany
Alexander Drenker, Fraunhofer Institute for Laser Technology ILT; Aachen Germany
Stefan Kaierle, Fraunhofer Institute for Laser Technology ILT; Aachen Germany
Presented at ICALEO 2010

In current manufacturing, conventional arc welding processes, such as MIG/MAG and submerged arc welding, are mainly used to produce joints of metal sheets over a wide range of materials and wall thicknesses. Yet the manufacturers are facing problems like a low productivity and reliance on the skill of operators to change process parameters to maintain weld quality, particularly during changeovers, i.e., when material and/or wall thickness is changed. Hybrid laser-arc welding offers many advantages compared with conventional arc or laser welding. Producing deep penetration welds comparable with laser welds, and at the same time having an improved tolerance to joint fit-up when compared with laser welding. The coupling of the two processes - laser and electric arc welding leads to an increased number of parameters and degrees of freedom, respectively. In the presented work a camera based coaxial monitoring system is employed to achieve controlled conditions for laser MIG/MAG hybrid welding processes.

This paper outlines the issues of weld quality and productivity improvement for manufacturing sheet metal through development of advanced sensors for the hybrid laser-arc welding process. Aim of the investigation discussed in the paper is to estimate the capabilities of a universal Open Diagnostics System (ODS) to capture on-line weld quality information in combination with positional data to allow operators to control the hybrid welding operation through a visual, user-friendly interface. Weld quality information will be provided by means of coaxial in-process camera-based analysis and on-line (camera) inspection of the weld root.