Fabrication of micro-hole using novel Maglev EDM

Abstract

In the current scenario, micro-manufacturing through the electro-discharge machining (EDM) process is a prominent technique for achieving desired complex micro/nano-features of any product. The precision and accuracy of producing features are the prerequisites of micro-machining. The current work aims to check the feasibility of the novel Maglev EDM for fabricating micro-holes on a thin nickel sheet (thickness = 500 μm). The study presents the viability of the newly developed system by comparing it with the conventional EDM process. A pure direct current power supply is assembled with a magnetic levitation-based gap monitoring mechanism to overcome the setbacks of conventional EDM. The novel setup utilizes the combined effect of the permanent electromagnet to diminish arcing and short-circuiting. The control parameters for the operation were 12 V open-circuit voltage and 2 A peak current while maintaining a duty factor of 95.564 percent. The measured discharge voltage and discharge current were 6.64 V and 900 mA, respectively. Tungsten rod (ø 650 μm) and deionized water were used as a tool and a dielectric medium, respectively, for the experiment. Further, the machined micro-hole and micro-tool analysis have been carried out using high-resolution microscopy, scanning electron microscopy and energy dispersive spectroscopy reports. The newly developed Maglev EDM’s feasibility to produce micro-holes on conductive materials has been confirmed in the present work with an average material removal rate of 40 μg/min.