Pulse-Current Wire Electrochemical Machining with Axial Electrolyte Flushing along a Rotating Helical Wire Tool.

The production of economical turbine slots with high efficiency and good surface integrity is a common concern in aviation manufacturing. State-of-the-art wire electrochemical machining (WECM) cannot afford the efficient precision machining of macro structures with thicknesses over tens of millimeters. This work investigated a pulse-current WECM process combining high-speed rotation of a helical wire tool and axial electrolyte flushing. Theoretical analysis and experimental results indicate that pulse frequency has a significant influence on the machining of thick specimens. The pulse-current charging process was prolonged with the increase in workpiece thickness, and it took up the majority of the pulse-on time at a pulse frequency over 50 kHz when the workpiece thickness reached 15 mm. The maximum feed rate first increased with pulse frequency, and then decreased from 20 to 100 kHz when a 20-mm-thick workpiece was being cut. Subsequently, the processes of electrolyte refreshment and product removal were maximized when the helical wire electrode rotated clockwise, and axial electrolyte flushing was applied. Finally, a fir-tree slot of 20 mm thickness with good dimensional consistency and good surface quality was stably processed at a rate of 5 μm s^-1 . [ABSTRACT FROM AUTHOR]