Analyzing the Dynamics of the Laser Beam Cutting Process

摘要： Instabilities of the melt flow dynamics at the laser cutting front lead to quality losses, due to the formation of striations at the resulting cut flank. The application of high-speed video diagnosis has turned out to be very instructive for a well-founded process analysis. In this way, it was found out for the first time that the melt film dynamics at the cutting front reveal characteristic frequencies that are nearly independent of process parameters. Interestingly, their local appearance correlates with the area of lowest roughness on the resulting cut flanks. This observation suggests the amplification of the characteristic frequencies in order to obtain a reduced roughness over the complete cut depth. Comprehensible rules for optimized laser beam and gas flow parameters can be determined based on the physical understanding of the origin of the characteristic frequencies.