Product Code: ICA11_202

Camera-Based Laser Beam Welding Sensor in the Near Infrared Spectral Range
Authors:
Holger Braun, TRUMPF Werkzeugmaschinen GmbH + Co. KG; Ditzingen Germany
Friedhelm Dorsch, TRUMPF Werkzeugmaschinen GmbH + Co. KG; Ditzingen Germany
Steffen Kessler, TRUMPF Werkzeugmaschinen GmbH + Co. KG; Ditzingen Germany
Dieter Pfitzner, TRUMPF Werkzeugmaschinen GmbH + Co. KG; Ditzingen Germany
Volker Rominger, TRUMPF Laser- Und Systemtechnik GmbH; Ditzingen Germany
Presented at ICALEO 2011

We demonstrate a novel process sensor system for use in laser beam welding that uses image processing of NIR images. Additionally to 2-dimensional process monitoring in the VIS spectral range, an NIR camera detects in the spectral range above 1 µm the welding spot and its proximity coaxially through the welding optic and delivers information from the focus, the weld pool and the thermal influence zone. The evaluation of the various areas allows a fast online characterization of the welding process and its results, which may serve as the input for active process control.
We present examples of laser beam welding of various materials and process parameters and the respective process sensor evaluation, using a multi-kW Yb:YAG thin disk laser.