Improvement of Surface Roughness in Electrical Discharge Machining by Using Ultrasonic Auxiliary Electrode

General discharge machining could remove the material by the high temperature instantly generated from the conversion of electrical energy to heat energy that it is suitable for processing high-hardness and high-strength materials. In this study, discharge machining matched with ultrasonic auxiliary electrodes is mainly used for processing workpieces to further discuss the effect on the workpiece surface roughness. The results reveal that workpieces processed with traditional default discharge parameters appear the worse surface roughness. The surface roughness of the high speed steel SKH9, after the use of ultrasonic auxiliary electrodes, presents smaller standard deviation and the better surface roughness.