An investigation of ultrasonic-assisted electrochemical machining of micro-hole array

Abstract

This paper uses an ultrasonic vibration-integrated array electrode for 301 stainless steel micro-hole drilling. The influence of machining parameters such as ultrasonic vibration amplitude, working voltage, pulse-off time and electrode feed rate on different processing characteristics are discussed. The experimental results show that the ultrasonic-assisted electrode array vibrating generates a periodic pressure difference for the electrolyte. The periodic pressure difference forms a pumping effect and a cavitation effect. The two effects can effectively renew the electrolyte in the machining gap and discharge the reaction product, gas and reaction heat from the gap. Machining speed can be increased by over 500% when the ultrasonic amplitude increases from 0.94 µm to 2.87 µm. Micro-hole drilling with the optimum experimental parameter combination of ultrasonic amplitude 2.87 µm, working voltage 11 V, pulse-off time 50 µs and electrode feed rate 5 µm/s can result in a minimum average diagonal length and a smaller amount of variation in diagonal length. It also improves the inlet and outlet taper angle of micro-holes.