Analysis of electrochemical behavior on micro-drilling of cast hybrid Al/(Al2O3p + SiCp + Cp)-MMC using micro-ECM process

Abstract

This paper presents the results of an experimental investigation on machining of micro-hole during electrochemical micromachining (ECMM) of stir-cast hybrid aluminum/(alumina + silicon carbide + carbon particulates) metal matrix composite. An ECMM set-up was developed and utilized for carrying out the experimental investigation. The supply current (Ip), supply voltage (v), pulse-on time (Ton), pulse-off time (Toff), electrolyte concentration (EC), and electrolyte flow rate (FR) were selected as process parameters. The effect of process parameters on material removal rate (MRR), electrode wear rate (EWR), surface roughness height (SR), taper cut (TC), over cut (OC), and micro-spark-affected zone (MSAZ) were analyzed through various graphs. The surface characteristics of the micro-drilled holes were analyzed using energy dispersive X-ray spectroscopy and scanning electron microscope techniques. Experimental results revealed that the MRR, EWR, TC, OC, and MSAZ increase with an increase in supply current, voltage, and pulse-on time. The optimal parametric combination for high MRR with low TC, OC, and MSAZ was found at 1.5 A supply current, 13 V supply voltage, 10 µs pulse-on time, 10 µs pulse-off time, 15 g/L electrolyte concentration, and 0.2 L/min electrolyte flow rate.