Wire Electrochemical Micro Machining Assisted with Coupling Axial and Intermittent Feed-Direction Vibrations

Wire electrochemical micro machining (WEMM) using ultra-short pulses has been recognized as a flexible and effective tool for producing planar contour micro-features. However, high-efficiency mass transport in the extremely narrow machining gap (several micrometers or even smaller) is still a great challenge. Here, a method of WEMM assisted with coupling axial and intermittent feed-direction vibrations is proposed. The mechanism of the mass transport in the machining gap using this method was theoretically analyzed with the results indicating that the proposed method was very beneficial for improving the mass transport rate in the machining gap, owing to the high flow velocity in both the feeding and axial directions. A series of comparative experiments with different vibration styles were performed, the results of which were in accord with those of the theoretical analysis. Then, the effect of wire feed length, traveling speed, and amplitude for the intermittent feed-direction vibration to the machining efficiency and quality was investigated. Finally, under one group of optimal machining conditions, a multi-slit micro-structure with small standard deviation (about 0.53 μm) of slit width (about 13.8 μm) and good surface roughness (about R a = 0.042 μm) was successfully fabricated using a wire electrode with the diameter of 10 μm.