Modelling of MRR and hole taper for ultrasonic assisted jet electrochemical micro-drilling process using Buckingham's π theorem

Abstract

Ultrasonic assisted jet-electrochemical micro-drilling (UAJet-ECMD) process integrates ultrasonic vibrations and jet electrochemical micro drilling process. In the present study, Buckingham's π theorem has been employed to model the process responses namely material removal rate (MRR) and hole taper of the UAJet-ECMD process with continuous DC voltage. The model has been formulated taking into account the experimental parameters namely voltage, electrolyte concentration, electrolyte pressure, inter electrode gap, pulse on time of ultrasonic vibrations and other physical properties related to ultrasonic vibrations such as speed of ultrasonic waves in the electrolyte, amplitude and frequency of ultrasonic vibrations. Electrochemical properties of work piece material namely chemical equivalent of copper and Faraday's constant were also taken into considerations. The use of regression analysis has been done to model the process responses. From the resultant π terms contained in the developed models, insignificant terms based on their percentage contributions were reduced and the models for both MRR and hole taper were modified. The formulated models for MRR and hole taper were validated with the statistical models obtained from experimental results.