Multi-Response Optimization during Electro-Discharge Machining of Super Alloy Inconel 718: Application of PCA-TOPSIS

Abstract

The present work aims to determine an appropriate setting of process parameters (viz. gap voltage, peak discharge current, pulse-on time, duty factor and flushing pressure) for achieving optimal machining performance during Electro-Discharge Machining (EDM) of super alloy Inconel 718 by using copper tool electrode. Experiments have been performed based on L25 Orthogonal Array (OA) design of experiment by varying each of the aforesaid process parameter at five different levels. The machining performances have been evaluated in terms of Material Removal Rate (MRR), Electrode Wear Rate (EWR), Surface Roughness (Ra), Surface Crack Density (SCD), White Layer Thickness (WLT), and Micro Hardness (MH) of the EDMed Inconel 718 end product. In this paper, two different optimization routes have been explored. The proposed optimization routes have been (i) Principal Component Analysis (PCA) followed by TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) and Taguchi method and (ii) PCA coupled with Combined Quality Loss (CQL) concept followed by Taguchi method. Application feasibility of aforementioned two optimization approaches has been compared herein through this case experimental research.