Analytical and experimental study on the integration of ultrasonically vibrated tool into the micro electro-chemical discharge drilling

Electrochemical discharge machining (ECDM) is a non-traditional machining process which is used to create micro-features on non-conductive materials. Micro holes and micro channels are the most interested features that have been fabricated by researchers. In recent years, some technical augmentations have been added to the ECDM process to achieve a more efficient machining process, but the employment of each augmentation in the most efficient way is not subjected. In this research, ultrasonic vibration is concentrated on the tool tip which directly and continuously effects on the machining zone and avoids global undesirable effects. For this purpose, modal analysis is used to design a special configuration which achieves the maximum amplitude of vibration in the tool tip. Also, an analytical model is presented for both of the electro-chemical discharge machining (ECDM) and ultrasonic assisted electro-chemical discharge machining (UAECDM) to study the effect of ultrasonic vibration on the thickness of gas film. Practical gas film thickness, machining speed, entrance overcut and tapering zone are studied for both of the ECDM and UAECDM to comprehensive understanding the effect of integration of ultrasonic vibration into the traditional ECDM process. Captures of gas film in different condition confirmed that ultrasonic vibration has reduced the thickness of gas film. Same behavior was achieved by employment of the analytical modeling. As a result, numerous small discharges were achieved which increased the material removal rate (MRR) and hole accuracy, simultaneously. Results showed that ultrasonic vibration can increase MRR up to 82%. Also, tapering zone and entrance overcut deviation as accuracy parameters improved 50% and 40%, respectively. (C) 2016 Elsevier Inc. All rights reserved.