The research focuses on the applicability of silver (Ag) and molybdenum disulfide (MOS2) nanoparticle synthesized in situ in dimethylformamide solution as dielectric material for micro-electro discharge machining. Ag nanoparticles (~120 nm size) and MOS2 nanoparticles (~20 nm size) were synthesized in dimethylformamide solution using a combination of nanoparticle solution synthesis routes. A setup for micro-electro discharge machining was developed in-house with an arrangement to generate spark at varying voltages. The setup was integrated with a precise linear height gauge to measure the spark gap during the experiments where Ag and MOS2 nanoparticles in dimethylformamide solution served as dielectric. The debris was collected and was characterized for each of the experiments. The feature size of the crater generated during the micro-electro discharge machining was also studied. The experiments were repeated with silver and MOS2 nanoparticle powder mixed with dimethylformamide as dielectric. It was observed that in situ prepared nanoparticles in dimethylformamide offered much better machining performance in terms of process stability, crater size and material removal rates. On use of in situ synthesized nanoparticle dielectric, the material removal rate increased by nearly two to three times whereas the spark gap increased by about two times.

We report a new method for tool positioning in micro-electro-discharge machining with multiple electrodes for generating parallel spark employing a combination of stepper motor and piezoactuator-based co-actuation method. The stepper motor was used for coarse positioning and the inequality arising due to difference in the tool size of multiple tools used in micro-electro-discharge machining was equated employing piezoactuation followed by electrical continuity test. Simultaneous sparks for two different electrodes could be observed employing this method. The voltage waveforms across the tool–workpiece interface also confirm the generation of simultaneous and parallel sparks across both the electrodes.