Investigation of Ultrasonic Vibration of Workpiece and Tool Rotation Effects on Dry EDM Process

Dry electrical discharge machining (EDM) is environmentally friendly method in EDM process which replaces the gas instead of liquid as dielectric fluid. The process called green electrical discharge machining. This work integrated the influences of US vibration of workpiece and rotation of tool on dry EDM characteristics. Power of ultrasonic table, rotary speed of tool and gas inlet pressure are the process variables, and this study has investigated the effects of above parameters on material removal rate (MRR) and surface roughness (SR) of SPK cold work steel . Firstly exploratory experiments were carried out to finding the best tool design on geometry and material points of view. Tools with numbers of one and two centerless holes on face surface and materials of Brass and Copper were trialed by considering of MRR. Results which obtained by preliminary experiments showed that the brass tool with two centerless holes had highest MRR. Then the effects of ultrasonic vibration, rotary speed of tool and gas inlet pressure on dry EDM performance were studied. Secondary results indicated that the ultrasonic vibration had a positive effect on MRR and negative influence on surface quality. And also rotary speed of tool improves the MRR and reduces the surface roughness. Also increasing in gas pressure improves both MRR and SR.

Keywords:

Dry Electrical Discharge Machining , Ultrasonic Vibration , Rotary tool , Material Removal Rate , Surface Roughness