Electrochemical micromachining on nickel and nickel-based superalloys with two-tone sinusoidal signal.

[Display omitted] • We introduce an innovative approach to electrochemical micromachining using a Two-tone sinusoidal signal and investigate the mechanism behind the reduced machining gap with this signal. • Using the Taguchi optimization method, we study the impact of the control variables on the micromachining process during micro-hole drilling, and results show that using the optimized parameters greatly enhanced processing accuracy. • We use this technology to machine the microstructures on 5-μm pure nickel sheet and hard-to-cut super alloy plates, and improve the machining accuracy to the nanometer level. Electrochemical micromachining is an emerging technology in the machining field. This method offers several advantages such as exceptional surface quality, minimal cathode depletion, and a high elimination rate. Often, an ultrashort pulse power supply is employed in electrochemical micromachining to address over-machining in non-processing areas. While reducing the pulse duration can enhance processing accuracy, its high cost and impracticality for regular production limit its development. This paper presents the use of a Two-tone sinusoidal signal as an alternative to ultrashort pulse in electrochemical micromachining. We investigated the mechanism behind the reduced machining gap with this signal. By drilling micro-holes in the nickel sheet to optimize parameters such as voltage, fundamental frequency, and harmonic order. Using the Taguchi optimization method, we studied the impact of these control variables on the micromachining process during micro-hole drilling. The study also focused on fabricating micro-structures using the best processing parameters. Our results showed that using the optimized parameters greatly enhanced processing accuracy. Moreover, we found that high machining accuracy could be achieved when working on hard-to-cut super alloy plates. [ABSTRACT FROM AUTHOR]