Solutions for technological performances increasing at ultrasonic aided electrodischarge machining

Abstract

The paper deals with researches concerning phenomenology and solutions for technological parameters improvement at finishing through electrodischarge machining (EDM) aided by ultrasonic (US) longitudinal vibrations of electrode-tool (EDM + US). The stability of EDM + US finishing process was obtained increasing the working gap through ignition voltage growing and amplitude decrease of US oscillations. Pulse energy minimization aimed to reduce the craters volumes produced by discharge. We used consumed power values to supply the acoustic chain (PcUS) so the created acoustic pressure was over the cavitation threshold, but simultaneously, the PcUS value was minimized in order to not damage the surface quality and even to reduce the surface roughness. The number of discharges within an oscillation period was maximized and thus, material amount removed by ultrasonically induced cavitation was increased. Machining high content carbon and alloy elements materials by frontal flat surface electrodes improves volumetric relative wear. The flexibility concerning acoustic chain construction can be increased by Computer Integrated Machining, CNC processing acoustic horns and electrodes, previously elaborated through CAD and CAE.