Influences and Optimization of Electrical Discharge Machining Parameters for Improving form Tolerances of Micro Hole on SiC Conductive Ceramic Composite

Advanced Ceramics find wide range of industrial applications. Cutting of advanced ceramic (SiC) is very difficult using conventional machining methods due to its low fracture toughness. In the past few years, researchers have claimed successful machining of ceramic composites using EDM process. Furthermore, increasing trend, necessity of miniaturization, micro components in MEMS and semiconductor industry, micro mould and dies, furnace, micro injection, stamping, fuel nozzles, micro probes, photo-masks and micro tools. etc, have demanded the development of micro-machining methods for advanced ceramics. Therefore, this research was focused on micro hole drilling-EDM of SiC. The optimization of micro drilling in electrical discharge machining process parameters of SiC to improve the multiple performance characteristics such as, high material removal rate, low electrode wear ,surface finish and accurate over cut was investigated and optimized by the Grey-Taguchi method. The influences of peak current, pulse on-time, pulse off-time and spark gap on electrode wear (EW), material removal rate (MRR), circularity(CIR), taper ratio(TR) and overcut (OC) in the micro drilling operation using EDM of SiC were analyzed. The experimental results show that high MRR, low TWR, accurate OC, better CIR, better TR under the micro drilling electrical discharge machining. Hence, it is clearly shown that multiple performance characteristics can be improved by using the GreyTaguchi method. KeywordSink EDM; electrode wear; material removal rate; over cut; CIR, TR, Grey-Taguchi method __________________________________________________________________________________________________