Abstract:
Electrical Discharge Machining which is a non-conventional machining process have
been introduced lately as a hybrid one assisted by techniques like ultrasonic vibration,
addition of abrasives etc. Application of these techniques infused with traditional EDM
has enhanced machining characteristics i.e. Material Removal Rate (MRR), Surface
Roughness (SR), Tool Wear Rate (TWR). This work is based on investigating the
machining characteristics, of a graphite Powder Assisted Electrical Discharge Machining
on Mild Steel & Inconel 718 with Mobil Velocite Oil No 04 as the dielectric medium.
The responses measured in the experiment are Material Removal Rate, Surface
Roughness and Tool Wear Rate whereas the factors have been Pulse-On Time, Pulse-Off
Time and Peak Current. Increase in Peak Current as well as Pulse-On Time resulted in
increased Material Removal Rate but decreased surface quality and tool surface integrity.
The results of the machining characteristics of Powder Assisted EDM have been analyzed
by means of Response Surface Methodology; Analysis of variance (ANOVA) and F-test
has been used to check the validity of regression model and determined the significant
parameters affecting the machining characteristics. The numerical optimization of the
factors and prediction of responses have also been duly observed.
