Machinability of Drilling on Metallic Glass for Micro-Hole with Renewable Dielectric in an Electric Discharge Machining Process

Electric discharge machining (EDM) stands out for its ability to perform no-contact machining of materials with desired forms by multi-pulse discharges. In this investigation, the machinability of drilling on Ti56Zr18Cu12, metallic glass, for micro-hole is investigated with renewable dielectrics in the EDM process. Machinability is investigated by examining performance indicators including material removal rate (MRR), overcut, edge deviation, and energy efficiency per volume (EEV) in relation to the process parameters, such as electrical and non-electrical parameters. The edges of the drilled holes are examined to investigate the micro-structural changes that occur in metallic glass as a result of micro-machining. The experimental results show that the maximal value of MRR of 0.0103 mm3/min is achieved when the pulse-on time of 30 μs and sunflower oil renewable dielectric is selected, and the minimum overcut and edge deviation of micro-hole drilling in Ti56Zr18Cu12 is 39.99 and 9.41 μm, respectively. Minimum overcut and edge deviation are obtained for colza oil, optimized by 38% and 70%, respectively, over the worst-case conditions. Multi-objective optimization on the basis of ratio analysis (MOORA) results in a 70% reduction in energy consumption of EEV compared to the conventional paraffin media process. In addition, a range of pulse-on time, pulse duty cycle, and renewable dielectric are identified using the MOORA technique while EDM drilling in metallic glass Ti56Zr18Cu12.