Phenomena and mechanisms in plasma-enhanced jet electrochemical machining

Abstract

This study presents a novel plasma-enhanced jet electrochemical machining (PE-JEM) method designed to improve the electrochemical machining performance while maintaining process stability. In jet electrochemical machining, the electrolyte jet usually exhibits free flow after increasing the inter-electrode gap, which leads to the natural formation of an air film between the electrode end face and the electrolyte. The high-speed imaging reveals the generation process and locations of plasma generation within the air film, with multiple plasma channels appearing simultaneously at different positions. The current and voltage signals demonstrate the periodic enhancement effect of the plasma, with the anode current density increasing approximately 2.7 times during plasma generation. Notably, the plasma generated in this method does not result in material wear at the tool electrode, ensuring process stability. The jet electrochemical machining experiment confirms significant performance improvements, with a 34.7 % increase in material removal rate and a 48 % increase in groove aspect ratio compared to conventional methods. When the electrode end surface was insulated to suppress plasma generation, the material removal rate and groove aspect ratio declined significantly. These findings highlight plasma-enhanced electrochemical machining as a highly efficient and stable technique for precision manufacturing applications.