Verfahren zur gratfreien trennenden Bearbeitung von Werkstuecken

WO 2011035777 A1 UPAB: 20110425 NOVELTY - The method for separatively processing workpieces in a burr-free manner by means of a focused laser beam that is deflected in two dimensions, comprises directing a laser beam emitted by a single-mode over laser or a disk laser at a workpiece surface to form a laser kerf in such a way that material removal is achieved only by ablation and the focal point of the laser beam is moved multiple times over the same positions of the workpiece surface along a cutting contour to be formed in a first phase of the processing. DETAILED DESCRIPTION - The method for separatively processing workpieces in a burr-free manner by means of a focused laser beam that is deflected in two dimensions, comprises directing a laser beam emitted by a single-mode over laser or a disk laser at a workpiece surface to form a laser kerf in such a way that material removal is achieved only by ablation and the focal point of the laser beam is moved multiple times over the same positions of the workpiece surface along a cutting contour to be formed in a first phase of the processing. The processing parameters of the method are changed in a subsequent further phase of the processing before the workpiece is completely divided, and the focal point of the laser beam is moved along the cutting contour to be formed with changed parameters, and the remelting and/or material removal is achieved at the edges of the kerf. A power density in focal point of 1x 107 W/cm2 and a feed rate of 150 m/min are held during the total first phase of processing, and the laser beam is focused so that the focal point has a diameter of 100 mu m. The power density is reduced in the focal point in the further phase of the processing. The feed rate is reduced during the further phase of the processing. The power of the laser beam is increased in the further phase of the processing. The laser beam is directed during the further phase of the processing defocused on the workpiece. The focal point on the workpiece surface has a diameter that is greater than the width of the laser kerf. The focal point is moved during the further phase of the processing oscillated with feed axis direction along the cutting contour so that the cut joint and its edges are irradiated during the movement. The feed speed of 500 m/min is fallen below in the first phase of the processing. The laser beam is defocused in the reduced power of the laser beam during the further phase of the processing. USE - Method useful for separatively processing workpieces in burr-free manner by means of a focused laser beam. ADVANTAGE - The method ensures easy and economical processing of workpieces in a burr-free manner by means of a focused laser beam with good quality