Abstract: In view of the difficulty in chip removal during micro electrical discharge machining process, and the resultant easy occurrence of abnormal phenomena such as short circuiting and arcing, which causes low material removal rate and high electrode wear ratio. A new piezoelectric self-adaptive electrical discharge machining system based on the inverse piezoelectric effect of piezoelectric ceramic is proposed, its machining principle is presented, and its machining characteristics are analyzed in terms of the experiments. This new technology can realize adaptive regulation of discharge gap depending on discharge conditions, facilitate chip removal, reduce the occurrence of arcing and shorting and can realize self-elimination of short circuits, thus the machining efficiency and stability of the working process can be improved greatly. Besides, this new technique can achieve micro-EDM with micro-energy at ultra low voltage. Examples explain that it can achieve stable machining process, attain high material removal rate, and the roundness of machined micro holes is good, which indicate that this new technology has wide application prospect in the field of machining micro holes.

Key words: Micro- electrical discharge machining, Piezoelectric actuator, Self-adaptive, Self-elimination of short circuit