Product Code: ICA11_105

Experimental Investigation on the Cut Front Geometry in the Inert Gas Laser Fusion Cutting with Disk and CO2 Lasers
Authors:
Leonardo Scintilla, Politecnico Di Bari, Department of Mechanical and Mangement Engineering (DIMeG); Bari Italy
Luigi Tricarico, Politecnico Di Bari, Department of Mechanical and Mangement Engineering (DIMeG); Bari Italy
Achim Mahrle, University of Technology Dresden, Institute for Surface and Production Technology, IOF Dresden; Dresden Germany
Andreas Wetzig, Fraunhofer Institute for Material and Beam Technology, IWS Dresden; Dresden Germany
Eckhard Beyer, University of Technology Dresden, Institute for Surface and Production Technology, IOF Dresden, Fraunhofer Institute for Material and Beam Technology, IWS Dresden; Dresden Germany
Presented at ICALEO 2011

In recent years, several studies on laser beam fusion cutting demonstrated significant differences in the characteristics of the well-established CO2 laser cutting and cutting with solid-state disk and fibre lasers. The absorptivity behaviour of metals shows essential quantitative differences for the corresponding wavelengths of both laser sources as a function of the angle of incidence between the laser beam and the material to be irradiated. In order to further the understanding of the involved phenomena, a series of cutting experiments with CO2 and disk lasers was carried out. Similar geometry of CO2 and disk laser beam in terms of focus diameter and Rayleigh length was used. In this work, the two dimensional stationary geometric shape of the cutting front is acquired by the longitudinal sections of the cut specimen. The cutting front geometry and the corresponding local angle of incidence are related with the absorptivity calculated in each point of the cutting front and consequently with the direct absorbed laser intensity. The effects of various laser processing parameters, as focal position and cutting speed, on the geometric shape of the cutting front have been analysed systematically on steel sheet 5 and 8 mm thick.