An Investigation on Electrochemical Discharge Micro-Drilling of Glass

Electrochemical Discharge Machining (ECDM) as an innovative spark-based micromachining method has been successfully applied for fabricating micro-holes in non-conductive brittle materials such as glass. However, the effects of influencing parameters for attaining accurate structures and dimensions remain to be explored. This paper attempts to analyze the effects of process parameters including applied voltage, tool immersion depth and electrolyte concentration on process outputs such as radial overcut (ROC), material removal rate (MRR), heat affected zone (HAZ) thickness and roundness error (RE) of the holes. In this regard, a set of experiments based on response surface experiment design method were conducted on soda lime glass. The relevant experimental data were used to establish mathematical models for process outputs using the response surface methodology (RSM). The obtained results show that applied voltage significantly increases the ROC, MRR, HAZ and RE. Also, electrolyte concentration has the same effects on mentioned outputs except the ROC. In addition, greater tool immersion depth decreases the MRR and HAZ thickness. The adequacy of the developed mathematical models was also evaluated by an analysis of variance (ANOVA) test. The relevant results show the capability of the proposed approach to investigate the ECDM process of glass.