Multi-response optimisation of EDM process machined by P/M electrodes made of micron and nano level particles

Abstract

ABSTRACT In electric discharge machining (EDM), the use of customised powder metallurgy (P/M) electrodes is of tremendous importance. The particle size of the P/M electrode, compaction pressure, and elemental composition of tool electrodes significantly influences the machining efficiency of the EDM. However, particle size variations were hardly studied, importantly when the particle size is at ‘Nano level’. In the present investigation, machine tool and electrode parameters are considered for evaluating the machining efficiency by measuring the material removal rate (MRR) and tool wear rate (TWR). The workpiece and tool electrodes are D2 alloy steel and WC/Co P/M electrodes, respectively. Taguchi’s L18 orthogonal array was used in the design of experiments. The parameters Particle size (PS), Peak current (IP), Compaction Pressure (CP) and wt% of Co (%Co) have all been found to have a substantial impact on improving MRR and TWR simultaneously. At the optimal combination of parameters, MRR was improved from 109.1 to 151.9 mg/min, and TWR was lowered from 7.1 to 5.9 mg/min with the proposed method. Predicted results are compared with confirmation experiments to validate the findings. The probable reasons that contributed to the enhancement of performance measures are discussed.