Implementation of micro-EDM for machining of nonconductive ceramics

Ceramic materials are, due to their extraordinary properties such as high hardness and biocompatibility, increasingly used in micro parts. In research, the electro discharge machining of nonconductive ceramic materials using an electrically conducting starting layer ("assisting electrode") has been successfully adapted to ZrO2 ceramics. In the current study, tests are carried out to determine the minimum feature size of micro structures and the influences of vibration superposition on the outcome and process speed. Optimized parameter settings are leading to a more stable and faster micro-EDM of nonconductive industrial grade ZrO2 ceramic material. Thus, aspect ratios of 5 for micro bores with diameters of less than 200µm can be realized and pole structures of 50µm width and aspect ratio of 10 could be obtained.