BRILAMET research project brought to successful conclusion

Using lasers to cut sheet metal is something that has typically been handled in the realm of CO2 and fiber lasers, though this may not be the case for very much longer:

Diode lasers are increasingly emerging as the light source of choice for a large number of applications, as can be seen from the BRILAMET research project that has just come to a successful conclusion.

There is a great deal of interest surrounding laser cutting, and events related to this topic often draw plenty of publicity. One recently-concluded research project in particular will likely attract even more attention, especially for applications in the sheet-metal industry, namely: the BRILAMET (brilliant high-power diode lasers for metal processing) joint research project.

This was carried out between July 2012 and June 2015 as part of the German Federal Ministry of Education and Research program entitled “KMU-Innovativ, Optische Technologien”.

During this period, the Laser Center at the Münster University of Applied Sciences (LFM) teamed up with the Dortmund-based LIMO Lissotschenko Mikrooptik GmbH to conduct extensive experiments in the area of precision cutting for thick metal sheets.

Initially, the project involved the use of a 2.5 kW high-power diode laser (HPDL) that was coupled to industrial CNC machining equipment. LIMO had used special micro-optics to optically connect the HPDL beam source modules.

Through an optical fiber, the HPDL beam was then guided to the cutting head, which was also developed by LIMO. LFM and LIMO employed the “Design of Experiments” (DOE) methodology to optimize the cutting process by experimenting with different nozzle geometries and diameters, as well as with other aspects.

As the project progressed, the experiments were expanded to include a 4 kW HPDL beam source, which likewise consisted of two laser units coupled together.

Among other things, the project showed that although a high-power diode laser operates at a relatively modest brilliance, it is well suitable for the rapid and precise fine cutting of 6-mm thick stainless steel (speed > 2.0 m/min., roughness Rz < 30 µm).

“The key ingredient here is not only the asymmetrical laser beam geometry but also the model for predicting machining results, which was developed during the project,” explains Dr. Jens Meinschien, VP, Innovations Management at LIMO. “By making further laser beam-shaping adjustments, cutting speeds of 2.5 m/min can even be achieved with 4 kW diode lasers.”