Performance study and mathematical modeling of grinding aided electro-chemical discharge drilling (G-ECDD) of soda-lime-silica glass

Electrochemical discharge machining (ECDM) has gained an immense attraction among the researchers during the past few decades due to its huge potential to process difficult-to-machine advanced ceramics. However, the limitations associated with ECDM in the close control of dimensional accuracy as well as repeatability need to be eliminated to make the process industry standard. Grinding aided electro-chemical discharge drilling can offer a solution to the above said limitations due to its hybrid nature of material removal mechanism involved. G-ECDD utilizes the grinding action of diamond coated solid or hollow tool and the electrochemical discharges for the material removal from the workpiece. In this work, a systematic investigation was conducted to study the effect of machining parameters like voltage, duty factor, frequency and electrolyte concentration on the G-ECDD performance (responses) which includes surface roughness and overcut. A two level full factorial experiment with centre points was conducted with soda lime glass as the workpiece. From the ANOVA results, the significant factors contributing to surface roughness are found to be voltage and duty factor, followed by frequency and concentration. For overcut, the significant factors are in the order of voltage, frequency, duty ratio and concentration. Regression models are developed for predicting the responses. An attempt is made to develop mathematical models for material removal rate (MRR) and surface roughness using the above mentioned observations considering both thermal aspects as well as grinding effect. With the help of confirmation experiments, the models are validated. The present work proves the potential of G-ECDD for performing high quality precise drilling of glass and reveals the effect of machining parameters on the process performance. (c) 2017 Elsevier Ltd. All rights reserved.