This paper reports the results of an experimental investigation
carried out to study the effects of machining parameters such as
pulsed current on material removal rate, diameteral overcut,
electrode wear and surface roughness in electric discharg
e
machining of En-31 tool steel (IS designation: T105 Cr 1 Mn 60)
hardened and tempered to 55HRc. The work material was ED
machined with copper, copper tungsten, brass and aluminum
electrodes by varying the pulsed current at reverse polarity.
The measurement of pulsed current by the Rogowski coil method is described.
The current transformer with a large number of turns
terminator has good short-time response, necessary for the sharp
current dip region
