Electrochemical Discharge Machining of Non-Conducting Ceramics

Abstract

The electrochemical discharge machining (ECDM) process is mostly applied for machining nonconductingengineering ceramic materials, such as aluminium oxides, zirconium oxides, and silicon nitrides,etc. Experiments on ECDM have been carried out according to designed experimental plan based on standardorthogonal array (L,) to identify the optimal parametric conditions of ECDM process using Taguchi methodof parametric optimisation. In this study, the signal-to-noise (SIN) ratio and the ANOVA analyses are employedto find the relative contributions of the main machining parameters, such as applied voltage, electrolyteconcentration and interelectrode gap in controlling the machining performance, such as material removal rateand radial overcut of the ECDM process. The confirmation of experimental results under optimal parametriccondition are provided to ensure the improvement in quality characteristics of the ECDM process. The highlypurified non-conducting zirconium oxide is used as workpiece material and aqueous KOH in stagnant conditionas electrolyte with three different concentrations (i.e., 15 per cent, 25 per cent and 20 per cent). The appliedvoltage of pulsed d.c. power supply has three levels of 50 V, 60 V and 70 V and the three different interelectrodegap setting considered for the experiments are 20mm, 30mm and 40rnm respectively.