Beam oscillation - periodic modification of the geometrical beam properties

Sheet metal with thicknesses above 8 mm has a distinct cutting performance. The optical configuration, composed of fiber diameter, collimation and focal length, allows for many opportunities to influence the stationary beam geometry. Previous analysis points out the limits of this method in the thick section area. The achieved cut quality of a stationary beam shape is restricted by the laser power. Most operators would like to improve the cutting results without changing their available laser sources, even for thicker materials. To overcome some limits, new approaches are desired. Within the present study an experimental investigation of fiber laser fusion cutting of thick section stainless steel was performed, by means of dynamical beam oscillation. The aim is to compare stationary and dynamical beam shaping, through evaluation of the cut quality, the kerf geometry, and the applied process parameters. The investigation emphasizes promising procedural possibilities for improvements of cutting performance in fiber laser cutting of thick stainless steel.