Experimental investigation of the influence of tools ultrasonic vibrations and external magnetic field on machining characteristics at EDM process

Electric discharge machining is one of the most widely used non-traditional machining techniques which use thermal energy for machining in small dimensions, machining complex shapes and machining hard materials with high strength such as ceramics and heat-treated steels. In this study the ultrasonic vibrations and magnetic field assisted EDM process as a new hybrid process was introduced and used for machining of AISI H13 too steel, to solve the EDM process limitations such as low material removal rate. In this investigation, several experiments were designed and performed based on full factorial method by selecting pulse current and pulse duration as most effective parameters of EDM process in order to study the effects of applying ultrasonic vibrations to tool electrode and external magnetic field around gap distance of EDM process, simultaneously, on material removal rate and tool wear rate. According the results, applying ultrasonic vibrations to tool electrode and external magnetic field around gap distance of EDM process, simultaneously, despite the increases of tool wear rate, increases the material removal rate as compared with EDM (60%), ultrasonic vibrations assisted EDM (40%) and magnetic field assisted EDM processes (55%) in all pulse durations and pulse currents except in pulse current of 32 A. In pulse current of 32 A, because of the interference of the influences of applying ultrasonic vibrations to tool electrode and external magnetic field around gap distance, the material removal rate and tool wear ratio are decreased.