Electrochemical micromachining based on sinusoidal signals with variable resistance

Reducing pulse duration is the sole effective strategy to improve the processing accuracy in ultra-short pulse electrochemical microfabrication. High cost and unsuitability in practical production also restrain its development. This study aims to propose a method based on sinusoidal signals with variable resistance. The bilayer capacitor cannot be fully charged to achieve a transient machining state. An equivalent circuit differential equation is established, and the resistance becomes an effective parameter to control the machining accuracy. The experimental result shows that the machining accuracy increases significantly with the increase in resistance. The approach is applied to machine microstructures and achieves sub-micron scale accuracy on a pure nickel sheet. The same superior machining accuracy can be obtained by machining microstructures on hard-to-cut superalloy plates.