Design and Development of IEG Control and Characterization of Micro-holes Generated Using In-house Developed μ-ECM Setup

Micro-electrochemical machining (mu-ECM) is a non-conventional machining process used for machining various micro-features on any conducting engineering materials with the required size and shape irrespective of the material's hardness. The present study focused on the machining and characterization of micro-holes machined on a copper plate of 300 mu m thickness with a hollow stainless steel tool of outer diameter 250 mu m, aqueous sodium nitrate (NaNO3) electrolyte, using the tailor-made mu-ECM experimental setup. The unique feature of the experimental setup is an indigenously made pulse generator circuit and closed-loop tool feed circuit made from a current-based sensor to maintain a constant inter-electrode gap between the tool electrode and the workpiece electrode during the machining process. The input process parameters selected for machining are voltage (V), electrolyte concentration (wt% C), and duty factor (% DF). The effects of these input parameters are studied on output responses like material removal rate, circularity, radial overcut, and taper angle using the grey relational analysis technique. The statistical significance of the input parameters and their interactions on the output responses are also analyzed using the analysis of variance technique. The topography of the machined holes at various experimental conditions is also studied.