Multi-Response Optimization of ECDM Parameters for Silica (Quartz) Using Grey Relational Analysis

Abstract

Electrochemical discharge machining (ECDM) has successfully demonstrated the micro-machining of pioneering engineering materials, regardless of their properties such as glass, quartz, silicon nitride ceramics, composites, etc. Yet numerous intrinsic challenges are there that should be addressed during the micro-hole drilling process with ECDM such as low material removal rate (MRR), high area of the heat-affected zone (HAZ), high hole tapering (HT), high radial overcut (ROC) and circularity error (CE). However, the determination of the input parameters’ optimum level for multi-response parameters is still a strenuous work. This present study investigates the machining performance of the ECDM process during the machining of silica (Quartz) through establishing the optimum combination of the level of the parameters for multi-response parameters. MRR, HAZ, HT, ROC, and CE were picked as response parameters. Experiments were performed in consonance with Taguchi’s L9 orthogonal array and response measurements were analyzed through Grey Relational Analysis (GRA) to identify the optimum levels of input process parameters for their combined fusion i.e. maximum MRR, minimum HAZ, minimum HT, minimum ROC, and minimum CE. Results exhibited that electrolyte concentration (wt.%) is the utmost governing input parameter followed by applied voltage (V) and inter-electrode gap ((IEG), mm) for controlling the multi-response parameters simultaneously. GRA optimized parameters were determined as 35 V, 15 wt.%, and 25 mm with 68.34% contribution only from the electrolyte concentration. Based on experimental investigation, micro-holes were successfully drilled on Silica (quartz) material with the success of the utilized method to assess the machining performance of the electrochemical discharge machining process.