Investigation on Multi-Tool Machining of Ag Using μ-EDM

Machining of micro-holes, micro-channels, and micro-textures with multiple numbers is significant in productivity improvement and cost-effective production. Micro-electro Discharge Machining (μ-EDM) is a thermal erosion technique to machine different micro-features with necessary precision and accuracy. The only constraint is it is a time-consuming process. The current study focused on machining multiple micro-square holes using in-house developed μ-EDM. The workpiece electrode is a 0.6 mm thick silver sheet, and the customized copper electrodes are fabricated using the wire-EDM method. Each tool electrode consists of a square pin size of 385 μm × 385 μm with 0.7 mm pitch, the number of pins varying from 1 to 10 pins. A total 10 number of experiments are performed with fixed process parameters as current of 1 A, voltage as 30 V, capacitance of 470 μF, Ton and Toff as 80 μs, and 120 μs. The responses like machining time, side gap, material removal rate (MRR), and tool wear rate (TWR) are analyzed. The analysis concluded that it could be possible to machine up to seven holes at a time with fixed parameters and available power. The same power is insufficient for 8–10 pins; it requires additional power. The number of pins increases MRR and machining time increase, and the side gap and TWR decrease. The research finding shows that employing multiple microelectrodes enhances the μ-EDM production rate of multiple holes in one stretch.