Application of Acidic Electrolyte to the Micro Electro Chemical Discharge Machining

Glass as a non-conductive material has special properties such as transparency, chemical resistance, and hardness. Traditional machining methods have noticeable limitations in their capability for shaping the glass parts. Electrochemical discharge machining (ECDM), as an advanced machining method, gives a chance to implement special processes on the glass. There are many effective parameters in the ECDM process and each of them has its special effect, but the influence of electrolyte type has been rarely evaluated in the literature. In this research, the effects of two types of NaOH and H2SO4 electrolytes on the glass have been studied. Electrolyte temperature, as another effective parameter on the chemical reactions, is also considered in these experiments. Surface quality, machining depth and overcut are considered as the machining outputs. The experimental results obtained in this research indicated that the application of H2SO4 acidic electrolyte after machining in NaOH electrolyte rather than machining solely in NaOH electrolyte has a significant effect on the walls of the holes. It is also observed that with a higher electrolyte temperature, the walls of the holes become smoother. It is also shown that, by applying two steps implementation of drilling and application of acidic electrolyte (NaOH/H2SO4), holes have a lower overcut, and the machining depth is improved up to 20.5% in the hydrodynamic regime.