INVESTIGATION OF DEBRIS PARTICLES DISTRIBUTION IN ELECTRICAL DISCHARGE MACHINING OF MICRO-HOLES ARRAY

Micro-holes array and micro-electrodes array are widely used in biomedical industry, aerospace industry and micro-electromechanical systems. The machining of micro-holes array is a difficult problem for traditional machining technology. Currently electrical discharge machining technology (EDM) is an alternative machining technology for the fabricating of micro-holes array in high strength and hardness of metal material because of it is free from mechanical force. However, distribution and concentration of debris particles in the discharge gap easily leads to the intensive distribution of discharge positions, which significantly influences machining performance of EDM of micro-holes array. In this study, a three-dimensional flow field simulation model of ultrasonic assisted EDM of micro-holes array is proposed by FLUENT software. The effect of ultrasonic vibration and the depth-to-diameter ratio on debris particles distribution in ultrasonic assisted EDM of micro-holes array will be investigated by numerical simulation. It is shown that reducing the depth-diameter ratio and increasing the ultrasonic amplitude and frequency are beneficial to enhance the exhaustion of debris particles out of the discharge gap and decrease the concentration of debris particles in the discharge gap. In addition, machining experiments are carried out.