Abstract: The micro-tool vibration can be used to improve processing stability and processing efficiency of micro wire electrochemical machining by removing electrolytic products in machining gap. A wire electrochemical micro-machining system with micro-tool vibration unit is developed, which is successful to meet the micro-machining requirements. The principle of micro wire electrochemical machining with micro-tool vibration is explained. A mathematical model of electrolytic products removing is presented. Micro-tool vibration is adopted as an effective way to remove electrolytic products and renew electrolyte in machining gap. Influence of micro-tool vibration on machining stability, feed rate and processing parameters is investigated. For the cases of wire electrode with and without the tool vibration system, comparison experiments are carried out. Results show that the vibration of 8 µm amplitude and 10 Hz frequency can be recommended for micro wire electrochemical machining, which provides better processing stability and processing efficiency. In contrast to wire electrode without the vibration, the parameters of applied voltage, pulse on-time and pulse period are optimized and machining accuracy is improved with the micro-tool vibration. With the optimal micro-tool vibration and processing parameters, a micro slit of 12 µm wide and complex-shaped micro involute gear and micro helix structure are fabricated on 0Cr18Ni9 stainless-steel.

Key words: Electrochemical machining, Processing stability, Stainless-steel, Vibration, Wire electrode