Effect of electrode hybridization in electrochemical micromachining of aluminum alloy composite

Abstract

The need for micro-level components in aerospace, automotive, and medical fields has continuously risen in recent years. In electrochemical micromachining (ECMM), due to the presence of hard particles like aluminum scrap alloy, it is difficult to make micro holes in such materials, as most micro holes appear with high overcut (OC). Also considering the need for higher material removal rate (MRR) and improved accuracy in micro-component fabrication, work is planned on the type of tool electrode and its insulation. Hence, different tool electrodes, including ceramic composite tool (CRCT), rubber insulated tool (RUIT), rubber filled hollow tool (RFHT), and normal tool (NRMT), are used to address these challenges. The effects of key input parameters, including machining voltage, duty cycle, and electrolyte concentration, were systematically investigated. An experimental result indicates that RUIT achieves MRR 2.09 times higher than NRMT. Also, CRCT demonstrates higher MRR, which is 1.7 times better than NRMT under the selected parameter set of 23 g/L, 13 V, and 80% duty cycle. Among the different tools, RFHT produces the lowest OC of 58.56 μm. Additionally, to reveal the effect of tool electrode impact on machining outcome and metal surface nature, scanning electron microscope (SEM) image analysis is carried out.