Manufacturing and verification of tools for ECF K.

The electrochemical milling with ultra short voltage pulses (ECF) displays an important progress in micromachining of hard materials. Machining a workpiece with conventional milling the removal takes place by shape cutting. Therefore mechanical forces are applied to tool and workpiece. In contrast, using electrochemical milling, the material removal occurs by an electrochemical reaction. Therefore the workpiece as well as the tool are submerged into an electrolyte and the surface of the workpiece is etched by a galvanic current. Hereby the so called working distance is formed between tool and workpiece, which goes linear with the pulse amplitude and pulse on time in a first approximation. As a result, there are no mechanical forces applied to the tool. This allows the use of very thin tools. To achieve the highest precision with this technique, it is necessary to manufacture very precise tools and to verify their shape and dimensions. In addition the use of rotating tools could be a promising strategy to speed up the ECF process and reduce the roughness. Therefore we introduce a method to produce very thin rotation-symmetric tools with high precision using the ECF technique. While the tool rotates the diameter is reduced by a one sided removal of material similar to machining with a turning lathe. To verify the shape and the dimensions of these tools a commercial laser measuring system for tool setting and breakage control was integrated into the ECF machine. Algorithms to determine the tool diameter and the toolshape are installed. Further algorithms have to be developed to characterize more details of the tool like tilt and run-out error.