Experimental Research on Small Holes by Electrical Discharge Machining Combined with Ultrasonic Vibration

EDM has two serious disadvantages that the material removal rate (MRR) is low and the surface roughness is poor, so much theoretical and experimental work has been done. The ultrasonic vibration electrical discharge machining (UEDM) can improve the MRR in small hole machining, but the mechanism and application of UEDM is still arguable. The experiments are done in D703F (high velocity electro discharge small hole machine). A transducer and horn are attached between the spindle and the electrode. The horn and the tool electrode are connected together by a chucking appliance. With the electrode vibrating, the UEDM is achieved. The comparison experiments of the MRR and the surface roughness are carried out with different electricity parameters (such as electric current, pulse duration, etc.) and different electrodes. The experimental results show that the reference point for UEDM is found and the new theory is proposed to explain the MRR increase and the value of surface roughness decreases.