Optimization of Electro-Discharge Diamond Drilling of Inconel 718 using Taguchi Method

Abstract

In this paper Taguchi method has been applied for optimization of electric discharge diamond drilling of Inconel 718 super alloy. Electrical discharge diamond drilling (hybrid process) process has been carried out on Inconel 718 using Taguchi L9 orthogonal array (OA). The effects of process parameters such as peak current (I), pulse-on time (Ton), pulse-off time (Toff) and drill speed (DS) on average surface roughness (ASR) have been studied to optimize and improve the process capabilities. Taguchi’s orthogonal array L9 (34) with three level of each four control factor were peak current, pulse-on-time, pulse-off-time and the rotational speed of tool electrode has been used in this study. In this study, the effect of varying process parameter with fixed machining time and constant spark voltage been investigated on average surface roughness of Inconel 718. Pulse-on time and peak current found the most influencing parameters for average surface roughness during electric discharge diamond drilling of Inconel 718. The optimum value of average surface roughness was found 1.88 μm. The percentage error between experimental and predicted values of average surface roughness was found 6.844%.