Effect of High Performance EDM on Surface Characteristics of AISI D2 Hardened Steel

Abstract

In this paper an attempt has been made to investigate the performance of an electrode made through powder metallurgy (PM) of copper tungsten during electrical discharge machining (EDM). Experimental results are presented on electrical discharge machining of AISI D2 hardened steel in kerosene with a copper tungsten (Cu35% - W65%) tool electrode made through PM method with a constant duty factor of 80%. In terms of high performance EDM process, higher peak current (>20A) and pulse duration (>400µs) with a high machining efficiency were applied. Experimental results have shown that machining at a peak current of 40A and pulse duration of 400µs yields the highest material removal rate (MRR) whereas machining at a peak current of 20A and pulse duration of 400µs yields the lowest tool wear rate (TWR). The surface characteristics of workpiece machined surface become more severe when shorter pulse duration be used at the constant duty factor. The optimum machining performance can be performed by the combination of pulse duration and peak current at 400µs and 40A respectively since the effect of TWR is so small at the varied parameters even at the highest MRR.