Carbon Nanotube Fiber Electrode Prepared by Charge Dynamic Regulation for Nano Electrochemical Machining

Nanoscale electrodes are critical to nano electrochemical machining (NECM), as they determine the structural dimensions of machined features, making their high-performance fabrication a key challenge. To address this, a novel method is proposed to fabricate nanoscale tool electrodes for NECM. The core method involves welding carbon nanotube (CNT) bundles onto the tip of tungsten-based metallic glass (MG) needles by charge dynamic regulation, which integrates controllable charge storage, electrostatic attraction, and arc discharge welding. This enables precise alignment of CNT bundles with the needle tip, improving straightness and bonding angle. Systematic experiments quantify the effects of needle tip radius and discharge electric charge quantity on welding quality. Results indicate that needles with different tip radii require distinct effective electric charge quantities to ensure successful CNT bundle welding, and a smaller tip radius requires a lower welding electric charge quantity. Subsequently, the CNT fiber electrodes are processed through micro-current etching, electric-field-assisted shaping, localized Joule heating, and Au sputtering to optimize geometry and conductivity. Ultimately, the optimized electrode is applied to fabricate submicron grooves with a minimum width of 500 nm on a nickel workpiece, representing the first application of such an electrode in extreme NECM and demonstrating its practicality and effectiveness.