Optimization of Beam Shapes for Laser Fusion Cutting by 3D Simulation of Melt Flow

The mean profile height and the angular tolerance of the cut surface are two important quality criteria in laser fusion cutting of sheet metals. Especially for laser sources with 1 µm wave length, the concurrent optimization for both quality features cannot be performed by plain Gaussian or tophat beam profiles. A dynamical 3D simulation reflects this behavior and enables testing of different beam configurations. It is shown that pure Gaussian beam profiles create the lowest mean profile height, while tophat shapes create the lowest angular tolerance. Comparing 10 µm laser sources it is shown that Gaussian beam profiles can reduce angular tolerance and mean profile height at the same time due to differing absorption characteristics. To optimize the cutting result for 1 µm laser sources, the effect of mixed beam profiles should be analyzed in prospective research.