Machining of micro-holes on borosilicate glass using micro-electro chemical discharge machining (μ-ECDM) and parametric optimisation

In the present paper, an attempt has been made to machine micro holes on 500 mu m thick borosilicate glass with 370 mu m diameter Stainless Steel (SS) tool using Micro-Electro Chemical Discharge Machining (mu -ECDM). The machining parameters considered for the analysis are Voltage (V); Duty Factor (% DF) and Sodium Hydroxide (NaOH) Electrolyte Concentration (wt% C).The output responses are Material Removal Rate (MRR), Tool Wear Rate (TWR) and Radial Over Cut (ROC). Experiments have been conducted using Taguchi L16 Orthogonal Array (OA). Signal to Noise (S/N) ratio technique has been used to optimise the machining parameters for individual output responses. The optimised parameters for maximum MRR are 65 V, 35 wt% C, 65% DF resulted in 890 mu g/min of MRR, for minimum TWR and minimum ROC, the optimised machining parameters are 50 V, 20 wt% C, 50% DF resulted in 25 mu g/m of TWR and 50 V, 20 wt% C, 50% DF resulted in 10.16 mu m of ROC. Further, the Grey Relational Analysis (GRA) technique has been used to optimise parameters and the obtained parameters are 50 V, 20 wt% C and 60% DF which resulted in 365 mu g/m of MRR, 25 mu g/m of TWR and 33.8 mu m of ROC.Abbreviations:ANOVA, ANalysis Of VAariance; DF, Duty Factor; ECM, Electro Chemical Machining; EDM, Electro Discharge Machining; GRA, Grey Relational Analysis; GRC, Grey Relational Coefficient; GRG, Grey Relational Grade; MEMS, Micro-electromechanical system; MRR, Material Removal Rate; OA, Orthogonal Array; ROC, Radial Over Cut; SS, Stainless Steel; S/N, Signal to Noise; TA, Taper Angle; TWR, Tool Wear Rate; mu -ECDM, Micro-electro chemical discharge machining