Patel, Jigar Bimal (2016-12). Ultrasonic Enhancement of Pulsed Electrochemical Machining. Master's Thesis.
Electrochemical machining (ECM) has gained prominence in the field on precise machining and has been subjected to a lot of study in order to bring its use to commercial levels. One of the key issues of electrochemical machining is the lack of proper flushing ECM by-products. Ultrasonic assisted ECM is often used to minimize the flushing issue. This study attempts a novel variation in ultrasonic assistance of ECM by introducing ultrasonic waves in the flowing electrolyte without vibrating tool or workpiece. This ensures intense agitation in the inter-electrode gap (IEG) with relatively simpler set-up. Aluminum 6061 is used as a workpiece material to drill holes. Stainless steel tubes coated with Teflon is used as tool. The Teflon coating minimizes the effect of stray current. Use of pulsed DC current and ultrasonic vibration improves the quality of the ECM'ed holes. The intense ultrasonic cavitation disturbs the anodic reaction in IEG negatively affecting MRR. On the other hand, the de-agglomeration of ECM by-products and depassivation of anodic workpiece improves surface roughness by approximately 50% and the taper angle of the hole by approximately 75%.