Numerical and experimental study of the effects of ultrasonic vibrations of tool on machining characteristics of EDM process

In the present study, an axisymmetric model for temperature distribution in single discharge of ultrasonic vibration-assisted electrical discharge machining process has been developed using finite-element method to get the dimensions of generated discharge crater on the surface of workpiece and provide a FEM model for material removal rate at this process. For this purpose, a new mathematical model for plasma channel radius was also developed and used in finite-element modeling. Then, due to good correlation between numerical and experimental results of recast layer thickness with maximum error of 6.1%, the developed finite-element model along with performed experiments was used to investigate the effects of applying ultrasonic vibrations to tool electrode on created crater dimensions, plasma flushing efficiency, and recast layer thickness at different pulse currents and durations. Also, the effects of pulse current and duration on depth, radius, and volume of created craters on machined surface at ultrasonic vibration-assisted electrical discharge machining (EDM) process was investigated. The experimental and numerical results showed that applying ultrasonic vibrations to tool electrode at EDM process increases generated crater depth and volume and plasma flushing efficiency and decreases generated crater radius and recast layer thickness.