Table of Contents

ABSTRACT

The basis of controlling the sink electrical discharge machining (EDM) process relies primarily on the empirical methods largely due to the stochastic nature of sparking phenomenon involving both electrical and non-electrical process parameters. Thus the performance of sink-EDM is commonly evaluated in terms of material removal rate (MRR) and tool wear rate (TWR). This paper presents the application of response surface methodology (RSM) for investigating the effect of tool taper angle with other process parameters like discharge current, pulse on-time and pulse off-time in sink-EDM process. The MRR and TWR mathematical models have been developed using the data obtained through central composite design (CCD). The lack-of-fit and adequacy of mathematical models were verified through the analysis of variance (ANOVA). Further, the confirmation tests were performed to ascertain the accuracy of the developed models. The investigation reveals that the MRR increases with tool taper angle, while the TWR decreases with increase in tool taper. From, the parametric analysis, it is also observed that the interaction effect of discharge current and pulse on-time is highly significant on MRR and TWR, whereas the main factors such as pulse off-time and tool taper angle are significant on MRR and TWR.

Keywords: EDM; MRW; MRR; TWR; RSM.