Simulation and experimental realization of μ-channels using a μED-milling process

Abstract

Machining of microchannels (µ-channels) on hard conducting materials can be performed effectively using a micro electric discharge milling (µED-milling) process. The method of bulk machining is considered in this work, as it takes less machining time than conventional layer-by-layer machining. However, the tool wear in this method occurs both in the side and bottom of the tool, which causes dimensional inaccuracy. Hence, to achieve the desired µ-channel shape, the technique of multiple-pass machining is introduced, wherein a dressed tool is used in each pass to compensate tool wear. The basic idea behind the work is to compute the number of passes and machining time required in achieving the shape. A computer-aided design-based algorithm is used to simulate the shape of the µ-channel and tool for a single pass and for further multiple passes. At the end of each pass, the volume of material removal and tool wear are estimated quantitatively. The desired channel shape is considered to be achieved when the volume of the material left-out is less than or equal to 5 per cent of the ideal volume to be removed. This paper elaborates on the procedure for single- and multiple-pass simulation to determine the number of passes and machining time. The results are validated with experiments for the desired µ-channel shape.