EXPERIMENTAL INVESTIGATION IN FABRICATION OF MICRO-CHANNELS BY USING ELECTRIC DISCHARGE MACHINING

Abstract

An experimental investigation was carried out to study the effect of process parameters on output responses in micro channel fabrication by electric discharge machining. Machining of micro channels was carried outon High Speed Steel material of T2 grade with die sinking type of EDM and Copper as a tool material. Pilot experimentation was conducted to study the effect of process parameters on the performance. OFAT approach was considered for pilot experimentation in which effect of parameters like current, pulse on time, pulse off time, lilt setting and gap voltagewas observed. It was found that all the parameters except pulse on time show the same behaviour as in conventional EDM process. In this case it was observed that MRR goes on decreasing with increase in pulse on time. As this is a micro channel cutting process scope for flushing debris from inter electrode gap is becomes ineffective. Therefore it leads to increased debris concentration resulting in arcing.'l'aguchi's technique was applied to obtain an optimal settingof the process parameters.The measured results and subsequentanalysis revealed that current was the only significant parameter for both MRR and TWR. [3othperformance measures increased with an increase in current but TWR was found to be negligible in comparison of MRR.As proposed work is a type of micro machining, i.e.. micro EDM: calculation of MRR and TWR in terms of weight cannot he precisely calculated and it will give inaccurate results. Therefore, for this work, calculation is carried out in terms of volume removed per unit time. Stereo microscope was used for measurement of dimensions for the calculation of volume of material removed.