Method for the production of drill holes in difficult to machine materials

A method for the production of drill holes in difficult to machine materials, in which a removal of material takes place in order to produce a drill hole by electrochemical erosion of material by an electrode that is moved in the longitudinal direction of the drill hole being produced in the direction onto the material to be processed at a feed rate, wherein the drilling proceeds in at least two steps, wherein, in the first step, the electrochemical processing takes place, in which the feed rate of the electrode is less than or equal to 20 mm/min during the electrochemical material erosion and the drill hole is fabricated with a drill hole diameter that is 0.05 to 2 mm smaller than a final diameter of the drill hole, and wherein, in a second step, the further processing of the drill hole to the final diameter takes place by machining processing or by erosion or by an electrochemical processing, in which the feed rate of the electrode is greater than or equal to 20 mm/min during the electrochemical material erosion.