Temperature modeling and in-process quality inspection in laser beam cutting of contour elements

For laser beam cutting of contour elements, the influence of the contour geometry has been examined due to a local and time-dependent preheating of the material. The paper presents a simulation of the temperature field in workpieces with different cutting contours calculated by the finite element method. By measuring the light emission from the cutting front and the molten material, the dynamical behavior of the cutting process can be characterized. The comparison of the local temperature at the time the laser beam passes and the obtained process signals with the resulting cut quality reveals the influence of preheating on the striation formation, on local cut surface defects, and on clinging dross. The simulation can help to detect critical contour elements for a given material and parameters set and to optimize the process parameters for a given contour.