Patent ID: 8350188
Filing Date: 2013-01-08
Classification: B23K

Abstract:
1. A method for material removal to a predetermined removal depth from a workpiece by means of a laser beam comprising one or more sub-beams, each of the sub-beams having a defined beam axis, wherein the axis of the laser beam or the individual axes of the sub-beams are guided along a removal line at a predetermined travelling speed and the laser beam has a predetermined spatial energy flow density that defines a Poynting vector S with a value I 0 f(x) and a direction s, the spatial energy flow density creating a removal face with an apex formed by the leading part of the removal face in the removal direction and said face creating a removal edge, the improvement wherein the respective incident angles αof the removal face formed by the normal vectors n of the removal face and the directions s of the Poynting vectors are set in such a way that they do not exceed a maximum value α max in a predefined region around the apex of the removal face, and wherein exceeding the maximum value is detected in the change from a small gouge, amplitude in an upper part of the removal edge to a large gouge amplitude in a lower part of the removal edge, wherein the incident angle α is given by: α=α[s*n]) with s=unit vector in the direction of the Poynting vector S, |s|=1, where |S|=value of the Poynting vector, and n =normal vector, |n|=1; and wherein α