On the Machinability and Formation of Gas Film Thickness in ECDM of Silica based Pyrex Glass

Electrochemical discharge machining (ECDM) stands out as a preferred method for microfluidic channel fabrication due to its ability to produce required shapes with the least thermal damage along with close tolerances and dimensional accuracy. Recently, there has been significant progress made in the domain of ECDM for parametric analysis, focusing on discharge regime characteristics, but precise control of the hydrodynamic regime remains a challenge. With this view, the present study has been targeted on analyzing the effect of various auxiliary electrodes on the formation of gas film thickness and discharge energy during the fabrication of microchannels using ECDM on silica-based Pyrex glass under varying conditions. Experiments were conducted on an ECDM setup to achieve near damage-free edges of microchannels on the surface silica-based Pyrex glass. Results show the effect of various auxiliary electrodes, applied voltage, and electrolyte concentration on gas film thickness, spark energy, rate of material removal (MRR), and width of overcut (WOC). The optimum parametric level of applied voltage, electrolyte concentration, and auxiliary electrode were 68 V, 35 wt%, and A2 auxiliary electrode, respectively and the best response values were 0.4134 mg min⁻¹, and 40 μm, respectively, for MRR and WOC. In addition, tool wear rate, heat affected zone, and surface morphology of fabricated microchannels was examined using scanning electron microscopy, optical microscope, and energy-dispersive X-ray spectroscopy.