Performance of Copper, Copper Tungsten, Graphite and Brass Electrode on MRR, EWR and SR of Aluminium LM6 in EDM Die Sinking

Abstract

This paper investigates the performance of copper, copper tungsten, graphite and brass electrode on machining characteristics of aluminium alloy LM6 (Al-Sil2) in the electrical discharge machine (EDM) die sinking. The relationship between the machining parameters such as peak current, voltage, pulse-on time, and pulse-off time on machining characteristics was studied. Design of experiment using orthogonal array of Taguchi technique is employed to design experimental matrix. The analysis was done by using the Minitab software version 16. From this study, it is found that graphite electrode produces the highest material removal rate (MRR) and low in surface roughness (SR) as compare to others electrode materials. Meanwhile, copper electrode has ability to generate highest Ra but low electrode wear rate (EWR). Copper tungsten electrode shows almost similar result with copper electrode however its hardness prevents from wear during machining process. Brass electrode shows low ability to withstand of spark energy that produces highest EWR. Thus, it shows that the objective of the experiment in terms of MRR, EWR and SR should be identified before specific electrode materials can be used for machining aluminium LM6 in EDM die sinking.