Performance optimization of ECM parameters for palladium coated tool electrode using multi-criteria decision analysis method

Electrochemical machining (ECM) is an important process for fabricating difficult-to-cut materials. It is a much more advantageous process for creating excellent surface quality on a wide range of conductive materials. In this research the electrode (cathode) is coated with less resistive palladium material through a sputtering process, and sodium electrolyte is added with 10 g.l-1 ascorbic acid in the aim of improving local electrolysis and reducing the sludge generation. The process parameters, specifically electrolyte concentration, machining voltage, duty cycle, and frequency, were varied on machining rate (MR) and overcut using the L27 orthogonal array experimental plan. ?Limination Et Choix Traduisant la REalit? (ELECTRE) is employed to find the suitable solution. Based on the ELECTRE method, the best factor combination is 29 g.l-1 electrolyte concentration, 12 V, 70% duty cycle, and 80 Hz frequency. The analysis of variance shows that machining voltage and electrolyte concentration are the considerable factors, with contribution percentages of 43.93% and 23.34%, respectively. As per the mean effect plot, the optimal combination is 29 g.l-1 electrolyte concentration, 12 V, 90% duty cycle, and 80 Hz frequency.