Effect of ultrasonic vibration object on machining performance of wire electrochemical micromachining

The development and application of wire electrochemical micromachining (WECMM) technology have become a research hotspot of non-traditional machining. However, a series of problems cannot be eliminated due to the machining products of micromachining gap, which leads to poor machining performance. This paper proposed a new method named ultrasonic vibration–added wire electrochemical micromachining (UA-WECMM) technology, which can solve the mass transfer problem in WECMM with extremely narrow gap. Firstly, the flow field of machining gap was simulated. The results showed that the pressure range of machining gap was larger and was more conducive to the renewal of electrolyte when ultrasonic vibration was added. Secondly, the effects of ultrasonic amplitude and ultrasonic vibration object on machining accuracy and surface quality were compared by experiments, which illustrated that the machining performance was greatly improved with the increase of ultrasonic amplitude of the workpiece. The slit width can be reduced from 196.2 to 151.2 μm, and the surface roughness can be reduced from R_a 0.863 to R_a 0.259 μm. Finally, the micro-gear structure with surface roughness of R_a 0.263 μm and depth-to-width ratio of 6.7:1 was fabricated, which proved that UA-WECMM technology is an effective technology for fabricating metal microstructures with high aspect ratio and good machining quality.