A Multi Criteria Decision Making (MCDM) based on TOPSIS and RSM for process improvement in electrical discharge machining of silicon nitride–titanium nitride ceramic composites

Abstract

This experiment is an attempt to choose the optimal machining parameters for electrical discharge machining (EDM) of silicon nitride–titanium nitride (Si3N4–TiN) ceramic composites based on MCDM approach. The electrical discharge machining have been conducted according to L21 orthogonal array with preferred input parameters like current (I), spark gap voltage (SV), pulse-on duration (Ton) and pulse-off duration (Toff). The response parameters measured are material eradication rate (MRR), electrode eradication rate (EWR) and surface roughness (Ra). The MCDM techniques namely Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Response Surface Methodology (RSM) are used to find the optimal machining parameters which provide better value of all responses. Also, scanning electron microscopy (SEM) is employed for examining the surface defects like micro-cracks, micro-pores, droplets, surface craters, globules, etc.