High-power diode laser enables laser cutting of thick stainless steel

Dortmund, Germany - There is a great deal of interest surrounding laser cutting of sheet metals. The Brilliant High-Power Diode Lasers for Metal Processing (BRILAMET) joint research project, which concluded in June 2015, involved using a 2.5kW high-power diode laser (HPDL) to conduct extensive experiments in the area of precision cutting for thick metal sheets. For the project, the Laser Center at the Münster University of Applied Sciences (LFM) teamed up with LIMO Lissotschenko Mikrooptik GmbH to conduct extensive experiments in this area.

The beam from the 2.5kW HPDL was coupled to industrial CNC machining equipment through an optical fiber to a LIMO cutting head. LFM and LIMO optimized 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 4kW HPDL beam source.

The project showed that although the high-power diode laser operates at a relatively modest brilliance in an asymmetrical laser beam geometry, it is well suited for rapid and precise fine cutting of 6mm-thick stainless steel (speed > 2.0 m/min., roughness Rz < 30 µm). Using laser beam-shaping adjustments, cutting speeds of 2.5 m/min can be achieved with 4kW diode lasers. But the LIMO experts were interested in more than using HPDL beam sources to optimize high-precision laser cutting processes. As a result, developers now know how to improve the components and, most importantly, the beam-shaping systems for kilowatt beam sources using an adapted optical, mechanical, and thermal design.

The work was part of the German Federal Ministry of Education and Research program entitled KMU-Innovativ, Optische Technologien (optical technologies in innovative small and medium-sized enterprises).

For more information, please contact Dr. Jens Meinschien at [email protected].