Optimal Machining Parameters of EDM in Gas Based on Response Surface Methodology

Abstract

This paper aims to establish an effective mathematical model with relation to electrical discharge machining (EDM) in gas based on response surface methodology (RSM). Moreover, the optimal combination levels of machining parameters for material removal rate (MRR) and surface roughness (SR) were also explored. The experimental tasks were implemented by a specific design of experimental method named central composite design (CCD) method based on RSM to develop quadratic regression mathematical model. The significant parameters and their interactions were examined by analysis of variance (ANOVA) to evaluate the importance on MRR and SR. The essential parameters of EDM in gas such as peak current (I_p), pulse duration (T_p), air pressure (G_P) and servo reference voltage (S_v) were chosen to investigate the effects on MRR and SR. From the analysis results, the optimal set of parameter setting levels were 12 A peak current (I_p), 750 μs pulse duration (T_p), 5 kg/cm<sup>2<sup> gas pressure (G_P) and 34 V servo reference voltage (S_v), and the optimization of MRR and SR were 1.99 mm<sup>3<sup> and 2.43μm as the machining parameters were set at the optimal levels.