The ideal selection of manufacturing conditions is one of the most important
aspects to take into consideration in the majority of manufacturing processes and
particularly in processes related to Electrical Discharge Machining (EDM). EDM die
sinking machines are used to machine conductive metals of any hardness or difficult
to machine with traditional methods. The problem in the capabilities of tool
electrodes which are not utilized at the optimum levels of the operating parameters
has attracted the attention of researchers and practicing engineers to manufacture tool
electrodes with highly great performance. In this work, an experimental design was
conducted to characterize the machining performances and surface integrity of three
different composition of copper tungsten (CuW) tool electrode in EDM of D2
hardened steel (58-62 HRC). Machining performances i.e. material removal rate
(MRR), tool wear rate (TWR), workpiece surface roughness (Ra) and micro-hardness
(MH) were studied for the three different composition of CuW tool electrode made
through powder metallurgy (PM) method. Machining variables were peak current
and pulse duration, meanwhile machining voltage, depth of cut and duty factor were
kept constant. The 65%W electrode is the best choice of CuW electrode on machining
D2 hardened steel due to the highest machining rate, reasonable tool wear rate and
acceptable surface characteristics. The improvement of MRR is obviously affected
by the increment of current intensity. MRR increased as the value of peak current
increased. The increment of pulse duration is not essentially improving MRR. There
is no clear relation between the alteration of pulse duration and MRR. However, the
MRR becomes the optimum at an optimal set of variables which is set at 40A and
400µs. The results of the machining performance can extent the availability of
database on EDM machinability and surface characteristics of D2 hardened steel for
machinist practices in industrial application of roughing operation
