On Performance Enhancement of the STED Process Using Modified Tool Electrode

Abstract

Shaped tube electrolytic drilling (STED) is an electrochemical machining variant that employs a tubular tool electrode to produce holes with a high aspect ratio on hard-to-machine materials. The tubular electrodes with a diameter below 1 mm produce undesired residue (center-peak) at the machining surface that hampers the machining rate. Therefore, this study attempts to improve the electrolyte flow and enhance the electrochemical dissolution through tool modification. The performance enhancement of the STED process in terms of material removal rate and average diametral overcut has been explored. The issues related to the limitations in material removal in the STED process are brought forth with the technique to resolve those difficulties. The experiments were conducted with the modified tubular tool, and the length of slits on the tool was selected based on the simulation insights and pilot study. The effects of input process parameters (applied voltage, tool feed rate, electrolyte concentration, and tool slit length) on the output responses obtained from the STED process are elaborated. Holes with diameters in the range 0.89–0.97 mm and 12 mm depth were fabricated. Further optimization of the process parameters in the design space is also presented to obtain sustainable process performance.