38. Investigation of Electrochemical Micromachining Process Using Ultrasonic Heated Electrolyte

Electrochemical micromachining (EMM) is one of the important machining methods for fabrication of micro-components on alloys and composites materials. Fabrication of micro hole is the important micro-machined feature, which are used in many components that find application in various fields such as aerospace, automobile, power circuit board (PCB), Ink jet nozzle, and the electronics industries. In this research, micro-hole is generated on 300 µm thick copper workpiece using 460 µm diameter stainless steel electrode. Sodium nitrate (NaNO₃) is considered as electrolyte and during machining process, the electrolyte is heated using Ultrasonic Vibration (USV). The experiments are planned according to L₁₈ Orthogonal Array (OA) using the machining parameters such as electrolyte concentration, machining voltage, duty cycle, and electrolyte temperature. The machining parameters are optimized using Multi-Objective Optimization of Ratio Analysis (MOORA) method. Weight of each response is calculated using entropy method as w_j for Material Removal Rate (MRR) = 0.4941 and w_j for Overcut (OC) = 0.5051. The optimal combination obtained using MOORA is 30 g/l of electrolyte concentration, 9 V of machining voltage, 55% of duty cycle, and 36° of electrolyte temperature. According to Analysis of Variance (ANOVA) results, the machining voltage contributes about 55% of overall performance. Additionally, Scanning Electron Microscope (SEM) images are taken for the further understanding of micro-hole profile.