Abstract: Through-mask electrochemical machining technology is a high-efficiency electrochemical machining technology for array structure processing, which is widely used in the processing and manufacturing of array group holes, group pits or group grooves of various difficult-to-process materials. At present, through-mask electrochemical machining mostly adopts the method of unidirectionally supplying electrolyte from the side. Although the flushing method is simple and easy to implement, due to the difference in the flow field between the front and back water surfaces of the processing area, the formation accuracy of the group hole structure is poor. For this reason, this paper proposes a periodic reversing fluid flushing technology to improve the flow field distribution in the processing area, thereby enhancing the forming accuracy of the group hole structure. Through numerical simulation and experimental analysis, the best reversing flushing frequency is determined, which proves that the reversing flushing technology can effectively improve the quality of group hole processing. Finally, an array group hole structure is processed by periodic reversing flushing technology. Compared with unidirectional flushing, the difference rate of the angle between the side wall and the axis of the hole is reduced to less than 1%, and a higher forming accuracy is obtained.

Key words: electrolyte flow field, through-mask electrochemical machining, group hole machining, difficult-to-machine materials