Improving machining efficiency in wire electrochemical micromachining of array microstructures using axial vibration-assisted multi-wire electrodes

Wire electrochemical micromachining (WECMM) is a promising approach for fabrication of high-quality microcomponents. However, its industrial applications remain limited owing to its relatively low machining efficiency, which is significantly affected by the efficiency with which electrolyte can be refreshed in the narrow machining gap. In this paper, a method of WECMM using axial vibration-assisted multi-wire electrodes with high traveling speed is proposed to improve upon the machining efficiency of WECMM. A flow-field model was established to simulate the flow field in the machining gap when the tool was traveling. A series of experiments are performed to optimize the machining parameters. Experimental results reveal that microstructures with negligible taper, high aspect ratio and good consistency can be effectively fabricated using this method. Finally, WECMM using 15-wire electrodes at a maximum feed rate of 5.0 μm/s is realized, at a total machining rate of 75.0 μm/s being achieved. With the optimal machining parameters, a multiple-slit microstructure with high aspect ratio of 20 is fabricated using 15-wire electrodes, and X-shape microparts of high surface quality (Ra = 128.0 nm, Rq = 162.0 nm and Rmax = 1.72 μm) are mass produced using 7-wire electrodes.