Optimization of WEDM Process Parameters on Surface Roughness and Study of Physical behaviour using SEM for Machining Aluminium Alloy Al 7075 using Brass Coated Copper Wire

Abstract

Wire Electrical Discharge Machining is one of the most effective Non-Conventional Machining method available to machine intricate shapes which are very difficult to machine with conventional machining methods, on electrically conductive materials having varying hardness. In this research work, an attempt has been made to study the effect of process parameters of WEDM on the Surface roughness. Input process parameters considered in this work are Pulse on time (T ON ), Pulse off time(T OFF ), Wire Feed (WF), Wire Tension(WT) and the Surface Roughness as response. Al 7075 Aluminium alloy was taken as work material and Brass coated copper wire as electrode to machine and the values of roughness obtained by varying the input process parameters were analysed using Taguchi method (L 27 orthogonal array). The measured values have been used to develop the mathematical model and the accuracy of the model was tested using Analysis of Variance (ANOVA) technique. Based on the predicted values the interaction graphs, were drawn between the Surface roughness and the process parameters taken for this study. It was construed that the pulse-on time has the highest impact on the Surface roughness followed by the Wire feed, Wire tension and the Pulse-off time. The surface roughness got increased with increase in wire feed. Finally optimum parameters have been arrived to achieve better surface roughness. WEDMed surface was also examined by using scanning electron microscope (SEM) and evinced that the physical behaviour of these process parameters on Surface roughness. Copyright © VBRI Press.