Sustainable electrochemical arc machining of SiCp/Al composites from current signals and energy control to applications

Electrochemical Arc Machining (ECAM) has demonstrated considerable potential for efficient machining of difficult-to-cut materials. However, the relationships between machining signals and material removal characteristics in ECAM are poorly understood. In this study, the impedance characteristics of ECAM machining circuit were investigated. Results show that the equivalent impedance of arc discharge is significantly less than that of Electrochemical Machining (ECM), leading to a higher arc discharge current. As the feed rate increases, the Inter-Electrode Gap (IEG) decreases, resulting in higher arc discharge frequency, longer sustaining time, and increased peak current. Arc discharges in a small IEG exhibit a high electrical equivalent, which is 2.34 times that of ECM. At a feed rate of 200 mm/min, arc discharge contributed to 93.59 % of the total material removal, achieving a Material Removal Rate (MRR) of 751.96 mm³/min. Furthermore, with increasing tool electrode feed rate, more electrical energy was effectively utilized for arc discharge processes. Under these conditions, a larger proportion of the arc discharge energy was allocated to the workpiece, minimizing the relative electrode wear rate to 4.61 %. The enhanced arc discharge effect led to a significantly recast layer, while the electrochemical effect remained relatively stable. Consequently, the groove dimensional characteristics and surface morphology were predominantly influenced by arc discharge behavior. This study elucidates the intrinsic relationship between material removal mechanisms and machining current in ECAM, thereby offering a foundation for machining optimization and industrial application. Finally, the ECAM technique was successfully utilized for the efficient machining of an optical load-bearing structure.