Patent ID: 8314358

Claim:
A method for thermal material-processing comprising the steps of: a) focusing an electron beam having a working spot onto a surface of a workpiece; b) bringing about a relative motion between the working spot of the electron beam and the workpiece wherein the working spot follows a processing contour; c) controlling the relative motion between working spot and workpiece in accordance with control variables that a control device derives from a stored ideal processing contour; d) prior to a welding operation determining an effective processing contour by: da) executing a relative motion of the working spot in relation to the workpiece in accordance with a stored data of an ideal processing contour with operating parameters that do not suffice for thermal treatment; db) superimposing a plurality of points of a scan motion which is directed transversely to the ideal processing contour and reaches beyond the latter on both sides; dc) measuring an intensity of the electron beam that is back-scattered from the workpiece as a function of a deflection of the scan motion; dd) placing the intensity ascertained in step dc) side by side in such a way that a graphical representation of the workpiece arises in which a progress of the relative motion in the direction of the ideal processing contour is plotted on one axis and a deviation of the effective processing contour from the ideal processing contour is plotted in a second axis.