Optimization of process variables in electric discharge machining (EDM) using Taguchi methodology

The present study engrossed with the functional relationship between the input and output parameters of the electric discharge machining (EDM). Four controllable machining parameters, viz. gap voltage (A), current (I-p), duty cycle (C) and pulse on time (T-on) have been chosen to ascertain the electrode wear rate (EWR) and surface roughness (SR) of AISI 420 material with copper electrode. Through Taguchi method, a design of experiment developed and it has been used to perform the experiment based on L16 orthogonal array (OA). During machining of AISI420, the highest influencing factor in EWR is I-p and least is C. Similarly, for SR T-on is most and C is least significant factor. From analysis of variance (ANOVA), for EWR, I(p )is having most significant 79.43% contribution and C is having least significant 2.36 % contribution. Similarly, for SR, T-on is having most significant 39.95% contribution and A is having least significant 11.79 % contribution.