A new method for preparing ultra-large aspect ratio microcylindrical electrode array by EDM.

Fabricating ultra-large aspect ratio microcylindrical electrode array efficiently, quickly, and reliably while maintaining high quality and low cost presents a continuous challenge. In this paper, a new method is proposed to produce ultra-large aspect ratio microcylindrical electrode array by taking advantage of the peculiar phenomenon that the front end of micro-prismatic electrode array becomes rounded after being worn in electric discharge machining (EDM). Specifically, micro-hole array with rounded outlets is machined on the workpiece using worn micro-prismatic electrode array, and then the micro-prismatic electrode array is converted into micro-cylindrical electrode array by reverse EDM. First, the simulation and analysis of the electric field distribution of the micro-prismatic electrode is carried out to reveal the mechanism of morphology evolution. Then, various micro-prism electrode arrays with different cross-sectional shapes were produced using the low-speed wire EDM technique. Next, the effects of cross-sectional shape, substrate material, peak current, and pulse width on electrode wear are studied. And the process conditions for rapid wear of the electrode front section into a circle and good wear consistency of the electrode array were optimized. The mathematical model of the front-end wear of the micro-prismatic electrode is also established. Following this, the development of electrode morphology was presented, transitioning from micro-prism electrode array to micro-cylindrical electrode array. The process of substrate shape change from square to circular holes was also discussed. The dimensional consistency of the micro-circular hole array was evaluated using image processing technology. Finally, a microcylindrical electrode array, measuring approximately 230 μm in diameter and having an aspect ratio of 18.15, has been successfully prepared and evaluated. This research has the potential to overcome the technological bottleneck of achieving high precision machining of micro-cylindrical electrode array with large aspect ratios. [ABSTRACT FROM AUTHOR]