LAUSR

This research was focussed on the effective utilization of the Powder-mixed Micro Electric Discharge Machining (PMEDM) process when using tap water as a dielectric medium for micromachining applications. Micro-holes of diameter 300 μm were drilled over Ti-6Al-4V plates. Firstly, the impact of process parameters on the machining performance was analyzed by using tap water without the additive. The effect of process parameters such as tool material, gap voltage, peak current, pulse ontime and duty factor on the Material Removal Rate (MRR), Tool Wear Rate (TWR), Overcut (OC), Circularity Error (CE) and Taper Ratio (TR) were analyzed by conducting the experiments based on Taguchi’s L18 design layout. The optimal parametric setting for multi-objective optimization was figured out through the technique for order of preference by similarity to ideal solution (TOPSIS). Secondly, keeping the process parameters at the optimal setting, the effect of additives in tap water dielectric based micro-EDM was investigated by using non-conductive, semi-conductive and conductive powders, namely Al2O3, SiC and Al of different weight concentration and particle sizes. The outcomes reveal that the type of tool has a very significant impact on the micro-EDM performance when using tap water as dielectric without additives. In PMEDM, the conductance of additives has a significant influence on the multi-objective performance characteristic. When using SiC additives in PMEDM, we recorded increase in MRR of 92.18%, decrease in TWR of 28.92%, decrease in OC of 18.99%, decrease in CE of 54.15% and decrease in TR of 24.78%.