Multi-performance optimisation of micro electro-discharge machining during deep micro-slots fabrication using foil tool electrode

摘要

This study attempts to investigate and optimise the effects of process parameters like voltage, sensitivity, duty factor and capacitance on performance characteristics such as material removal rate (MRR), tool wear rate (TWR), width expansion, length expansion and depth of slot during fabrication of deep and long micro-slots on brass work material by micro electro-discharge machining (micro-EDM). Copper foil is used as tool electrode of thickness 240 μm and width of 8 mm shaped by wire-cut electro-discharge machining. The randomised experiments were performed twice and mean response is considered for analysis to achieve accuracy in the results. Single-optimal parametric setting conditions obtained from the grey relational analysis (GRA) and confirmatory test results showed an improved machining performance of the process. Capacitance is observed to be the most influencing parameter followed by duty factor, sensitivity and voltage. Also, the feasibility of copper foil as a tool electrode is analysed and found high machining rate with more accurate micro-feature geometry.