EFFECT ON PERFORMANCE MEASURES DURING DIE SINKER EDM OF AMMC BY EXTERNAL DIELECTRIC FLUSHING SYSTEM

One of the important parameter in electrical discharge machining (EDM) of aluminium metal matrix composites is dielectric flushing pressure which is often not given attention due to its inbuilt presence inside the EDM set-up. Present work investigated the effect on material removal rate, tool wear rate and surface roughness with the variation of dielectric flushing pressure during EDM of 10wt.%Al2O3/AA2014. The composite was manufactured via mechanical stir casting route. For carrying out experiments on the available die sinker EDM to observe the influence of flushing pressure, a new external flushing system was developed to achieve high pressure.  Kerosene oil was used as dielectric oil instead of EDM oil supplied with the machine. Only pulse current (I) was varied as an EDM input parameter considered whereas voltage (V), pulse on time (Ton) and pulse off time (Toff) were kept constant. It is found that material removal rate invariably increases with an increase in flushing pressure of dielectric oil whereas surface roughness behaves opposite. However, no significant differences are observed for tool wear rate.