Improvement in performance during micromachining of borosilicate glass with temperature-stirring-assisted ECDM

With the advent of new technologies, there is an enormous increase in the need of devices with micro features on glass for u-Electro-mechanical Systems (MEMS) and medical devices. In the present scenario, Electro Chemical Discharge Machining (ECDM) is an evolving procedure to micromachine the glass due to constraints of existing processes. However, insufficient electrolyte replenishment, poor flushing and instability in the process deteriorates the performance of ECDM. To improve the performance of ECDM, the present research discusses the concept of Temperature Stirring assisted ECDM (TS-ECDM), having the capability to stir the electrolyte and control the electrolyte temperature. In TS-ECDM, the synergistic interaction of the electrolyte temperature with electrolyte stirring generates uniform and stable thermal discharges, required to improve the process performance. The response surface based Genetic Algorithm (GA) has resulted in the following optimum values of micro hole characteristics in TS-ECDM: Machining Rate (MR) = 320.31 um/min; Hole Overcut (HOC) = 368.31 um and Taper Angle (TA = 23.60 degrees). By comparing the results with ECDM process, the TS-ECDM process rendered 56% higher MR, 43% lower HOC and 51.79% lower TA with respective optimal parametric settings. Furthermore, the characterization of machined micro holes exhibited improved flushing and accentuated etching in TS-ECDM, which helped in achieving the improved response characteristics. Based upon this investigation, TS-ECDM has the potential to be an industrially feasible process in the micromachining of borosilicate glass.