Abstract:
In the present work, an attempt was made to use ultrasonic energy to augment the performance of electrochemical discharge trepanning (ECDT) process. The effect of various process parameters such as applied voltage, pulse on time, tool rotation rate and power rating on quality characteristics (over cut (OC) and depth of penetration (DOP)) of machined work materials was experimentally investigated. The underlying process mechanism for ultrasonic assisted ECDT (UA-ECDT) process is proposed by considering the high speed images of gas film, mathematical formulations, electrical signals and simulation results as evidences. A comparative analysis between ECDT and UA-ECDT was performed. The experimental results reveal that the integration of ultrasonic vibrations in ECDT process facilitates evacuation of the sludge/debris from the machining zone. Also, it generates thin and stable gas film over the tool electrode. Therefore, the use of UA-ECDT improves the energy channelization index (ECI), and it exhibits 10 times more ECI than the ECDT process. The second-order mathematical models were developed to determine the relationship between input process parameters and quality characteristics (OC and DOP). The developed models are in good agreement with the experimental results and exhibit an average error of less than 3%. Additionally, a desirability approach was employed to conduct the multiobjective optimization for the minimization of OC and maximization of DOP. The parametric combination of applied voltage of 60 V, pulse on time of 3 ms, tool rotation rate of 42 rpm and power rating of 17% is recommended to perform the UA-ECDT process
