The wear of foil queue microelectrode in 3D micro-EDM

Based on a planned process design path, a foil queue microelectrode (FQ-microelectrode) is applied sequentially in micro-electrical discharge machining (micro-EDM) in which the micro-EDM results can superimpose to produce the 3D micro-structure. However, in this process, each foil microelectrode (F-microelectrode) inevitably experiences wear, and the wear has an unfavorable effect on the machining accuracy of 3D micro-structure. In this study, the wear of F-microelectrodes for different technological parameters is studied in detail. The experimental results show that the first three pieces of the F-microelectrodes exhibit serious wear, and the wear values are all over 7 mu m. As the processing proceeds, the wear of the microelectrode gradually decreases to 2 mu m, as a result of an improvement in the processing environment. To ensure the machining accuracy of 3D micro-structure, this paper compensates the wear of the first three pieces of the F-microelectrode through rough and finish machining. Finally, based on the experimental results, a 3D micro-structure with good form accuracy can be fabricated in cemented carbide with pulse width T-on = 80 ns, pulse interval T-off = 160 ns, and machining voltage V = 100 V.