Laser Welding Processes Visualized in Real Time

A new x-ray video facility put into operation in November at the Institute for Laser Tools of the University of Stuttgart makes it possible to visualize laser processes in real time via x-ray video, for the first time in Europe.

X-ray video sequences with a frame rate beyond 1000 fps were recorded for the first time on Nov. 23, 2010. A laser deep-penetration welding process in 6-mm-thick aluminum was recorded with 5000 fps at a resolution of 512 x 512 pixel. The recording time was more than one second. This is an unprecedented performance and will open up significant new insights into the fundamentals of laser material processing, researchers said.

With this high-resolution view into the interior of the workpieces the researches at the institute (abbreviated IFSW from the German, Institut für Strahlwerkzeuge) will be able for the first time to investigate the shape and above all the highly dynamic changes and of the capillary and the movement of the surrounding melt which are created by the laser beam during welding. The knowledge gained in this way is important to understand and to overcome current limitations caused by instabilities such as splattering, pore formation or humping that occur for instance at high welding speeds.

For more information, visit: www.ifsw.uni-stuttgart.de