Abstract
Recent advances have established electrochemical discharge machining (ECDM) as an effective alternative to electrical discharge machining (EDM) for producing microholes in conductive materials. However, ECDM leaves non-uniform layers, including recast layers and heat-affected zones, rendering it unsuitable for materials vital to aerospace, defence, and biomedical applications. To address this issue, the present work investigates a novel ECM-based frugal engineering process known as simultaneous electrochemical and electrodischarge machining (SECEDM) for microhole fabrication. To evaluate the process effectiveness, the machining results of the SECEDM process were compared with ECDM, EDM, and ECM. The obtained results present the fundamental distinction between the process mechanism of SECEDM and ECDM. SECEDM has been reported to produce microholes with improved machined surfaces characterized by their freedom from recast layer and ECDM-induced defects. Moreover, SECEDM facilitated meticulously controlled high-speed anodic dissolution of work material, surpassing the material removal rate achieved through ultrasonic assisted-ECDM (U-ECDM) ECM and EDM processes by 2.67, 4.2, and 6.2 times, respectively. Furthermore, the substantial 67.72% and 68.82% reduction in the average machined hole diameter than ECM and U-ECDM respectively, with a noteworthy 13.69% enhancement in average roundness error achieved while maintaining the repeatability accuracy with an accuracy range within +0.009 mm through SECEDM process underscore SECEDM?s accuracy and repeatability. Also, lower surface roughness by 31.6% and 68% compared to ECM and EDM, along with reduced carbon and oxygen content, signifies the SECEDM process efficiency in microfabrication.
