Abstract: For the complex physical change and poor observability of the radial ultrasound rolling eletrochemical micromachining (RUR-EMM) gap physics field, the coupling effect of multi-physical field in machining gap is studied based on the numerical simulation method. A multi-field coupling theory model of electric field, two-phase flow field, temperature field and sound field in machining gap is established. Based on the proposed model, the variation rule of multi-field coupling interaction and the forming rule of micro dimple under multi-field coupling are obtained by numerical simulation method. Results show that the electrolyte in the gap flows into and out of the machining zone with vibration frequency of 20 kHz, amplitude of 10 μm, machining gap of 50 μm, cathode rotating angular velocity of 0.6°/s, and electrode conductivity of 7.9 S/m. The current density periodically changes with vibration cycle, and the temperature of electrolyte increases with the combined action of ultrasonic vibration and electrochemical reaction. Compared with rolling electrochemical micromachining (R-EMM), the gap temperature and current density of RUR-EMM are increased by 3.63% and 1.45 times, respectively, and the dimple depth of RUR-EMM is increased by 14.21%. This is because the pulsating flow field in the gap promotes the discharge of products effectively. The experimental results of micro-dimple machining verify the correctness of the theoretical model. The error between the simulated and experimental machining depths is less than 17.07%. Key

Key words: electrochemicalmicromachining, micro-dimple, ultrasoundvibration, rollingmachining, multi-physicalfield