Investigation on Electrochemical Discharge Micro-Machining of Silicon Carbide

Electrochemical discharge machining (ECDM) process has great potential to machine hard, brittle and electrically non-conducting materials in micron range. The objective of this paper is to investigate into electrochemical discharge micro-machining on electrically semi-conductor type silicon carbide (SiC) material so as to study the effects of applied voltage, electrolyte concentration and inter-electrode gap on material removal rate (MRR) and radial overcut (ROC) of micro-drilled hole. Experiments were conducted based on L9 array of Taguchi method with stainless steel µ-tool of 300µm diameter using NaOH electrolyte. An attempt has been made to find out the single as well as multi-objective optimal parametric combinations for maximum MRR and minimum ROC. The single-objective parametric combinations were selected as 45V/20wt%/20mm and 25V/20wt%/40mm for maximum MRR and minimum ROC respectively whereas multi-objective optimal parametric combinations was found as 25V/20wt%/40mm. Further mathematical models have been developed between the above machining parameters and characteristics.