Optimization of machine machining parameters in EDM of silicon nitride-titanium nitride based on RSM

Abstract

EDM of silicon nitride–titanium nitride ceramic composites with copper electrode was carried out here. Input factors of outstanding significance like current (I), spark gap voltage (SV), pulse-on duration (T on ) and pulse-off duration (T off ) were selected to calculate listed technological characteristics. The output responses measured were material abrasion loss (MRR) and electrode abrasion rate (EWR). Also, the distinguishing face of the EDM technique is delved by RSM (Box-Benhken method) based on Design of Experiments (DOE) and experimental results are evaluated by Analysis of Variance (ANOVA). Furthermore, L 29 orthogonal array (OA) based on the DOE to carry a row of machining has been followed here. From experimental outcomes, it is apparent that the current is the highly significant parameter among other factors as it alters both material abrasion loss and electrode abrasion rate. On the other part, difference in the pulse-off duration did not affect the responses. The higher material abrasion loss is obtained when current and pulse-on duration is higher and the increased gap voltage and lower current reduces the EWR. The higher MRR is obtained for current – 6 amps, pulse-on duration – 7 µsec, pulse-off duration – 10 µsec and spark gap voltage – 35 V. Reduced EWR is obtained for current – 4 amps, pulse-on duration – 6 µsec, pulse-off duration – 10 µsec and spark gap voltage – 40 V.