TY - JOUR T1 - Study of the effect of tools ultrasonic vibrations and external magnetic field on machined surface integrity at EDM process TT - بررسی تاثیر همزمان ارتعاشات فراصوتی ابزار و میدان مغناطیسی خارجی بر سلامتی سطح ماشینکاری شده در فرآیند EDM JF - mdrsjrns JO - mdrsjrns VL - 18 IS - 7 UR - http://mme.modares.ac.ir/article-15-16818-en.html Y1 - 2018 SP - 97 EP - 107 KW - Electrical Discharge Machining KW - External Magnetic Field KW - Tools Ultrasonic Vibrations KW - Machined Surface Integrity N2 - Despite the unique usage of electrical discharge machining process at machining in small dimensions, machining complex shapes and machining of high-strength parts such as ceramics and heat treated steels, which can’t be machined by traditional machining methods, low machined surface integrity achieved by electrical discharge machining process is one of the most important limitations of this process. In this investigation the machined surface integrity will be improved by applying ultrasonic vibrations to tool electrode and external magnetic field around gap distance of electrical discharge machining process, simultaneously. So several experiments were designed and performed based on full factorial method by selecting pulse current and pulse duration as the most important input parameters, in order to study the effects of pulse current and duration on surface integrity of workpiec machined by this hybrid process and to investigate the effects of tools ultrasonic vibrations and external magnetic field on machined surface roughness and integrity of machined surface. According the results, machined surfaces roughness is increased by applying ultrasonic vibrations to tool electrode and external magnetic field around gap distance of electrical discharge machining process, simultaneously, while the SEM pictures of machined surfaces showed that the, amount of created surface cracks, blowholes, globules and beads of debris are decreased and integrity of machined surfaces by EDM process is improved by applying ultrasonic vibrations to tool electrode and external magnetic field around gap distance, simultaneously. M3 ER -