Analytical modelling of material removal rate and surface finish in Maglev EDM on Ti-6Al-4 V

At present, the machining performance of the existing Electrical Discahrge Machine (EDM) technology depends on the commonly used pulsed power supply and gap control servo mechanism. The complexity and high cost of pulsed power supply and gap control servo mechanism reflects in elevated product cost. In current work, a simple electrical circuit with bipolar electric and permanent magnet was therefore developed to control the voltage. In order that, the tool electrode can be levitated over the workpiece at the desired distance (electrode gap). In present work a prototype is fabricated with DC power supply and magnetic levitation mechanism. The experiments were conducted on Ti-6Al-4 V alloy with a brass tool, to evaluate the superiority of maglev EDM technology over the existing EDM. The capabilities of maglev EDM reveal by providing stable discharge waveforms and the absence of short-circuit phenomena at significantly high duty factor. In addition to the fabrication of prototype, a predictive model is also formulated by dimensional analysis, based on material removal rate (MRR) and average surface roughness (SR). The reported experimental results of conventional EDM were used to formulate this model. The maglev EDM has shown higher MRR and surface roughness than what the predicted results did. During the experimentations, a specific energy of maglev EDM was observed comparable with reported results. Although, the proposed maglev EDM technology is in early stage but the performance is significantly competitive with the existing EDM. Further research in this field shall help to develop a feasible, economically sustainable alternative of existing EDM technology which is costly and complex in its present form.