Research on Machining Gap Distribution in Wire Electrochemical Micromachining

Wire electrochemical micromachining (WECMM) has become a research hotspot in recent years due to its advantages in machining metallic microstructures. Profiles of metallic microstructures fabricated by WECMM are determined by the machining gap distribution. This paper focuses on equilibrium machining gap distribution in WECMM. A two-dimensional electric field model of WECMM was established and the evolution process of slit profile was investigated. It was found that in machining equilibrium status, the machining gap gets the minimum value at the wire electrode feeding direction and exponentially increases with the increase of the induced angle between the wire electrode normal direction and its feeding direction. Furthermore, the effects of wire electrode diameter, machining voltage, and wire electrode feed rate on the equilibrium machining gap distribution were studied through machining simulation. The quantitative relationship among the machining gap at any wire electrode normal direction, the machining voltage, and the wire electrode feed rate was determined through function fitting. Finally, machining experiments were carried out to verify the regularity of the machining gap distribution. Experimental results are basically consistent with the simulation and function fitting results, with the ratio of the calculation error to the experimental value less than 12.78%.