Process Parameters Optimization of EDMed Surface of Titanium-Grade-4 Alloy Using Topsis Coupled with Taguchi Philosophy

Abstract

EDM is one of the non-conventional machining systems. It is a specialized thermal machining process which is used for machining parts of varying hardness and complex shapes. The major drawback of this system is that it has a lower machining rate. As there is no contact between the work-piece and the tool, so it is independent of the hardness of the work material. Titanium-Grade 4 (3.7065, R50700) finds its application in the aerospace industry. Machining of titanium was not an easy task, as it has poor thermal conductivity, higher pressure load, non-uniform chip thickness, etc. Peak current, pulse on time, and voltage were taken as input control parameters, whereas material removal rate, tool wear rate, and surface roughness were taken as response parameters. Desirability function was used to design the experiments using the L9 orthogonal array. The effects of each parameter on the response while machining using a copper electrode were studied.