Electrochemical machining of blades by using tapered cathode sheet with micro-grooves structure

Abstract

The combined electrode with cathode body and cathode sheet is widely used in the electrochemical machining of ruled surface parts. Due to the thickness of the cathode sheet, however, stray corrosion of the side wall of the cathode sheet will affect the machining accuracy and surface quality of the workpiece. In order to suppress stray corrosion, a tapered cathode sheet with a micro-grooves structure is proposed in this paper, which reduces the intensity of the stray electric field by increasing the distance between the side wall of the cathode sheet and the workpiece. According to the electric field distribution, the current density on the surface of the machined anode workpiece decreases as the cathode taper angle increases. In addition, to enhance the liquid-phase mass transfer, a micro-grooves structure was fabricated in the side wall of the tapered cathode sheet. Through the numerical simulation analysis of the flow field, the micro-grooves structure reduces the flow resistance of the electrolyte and suppresses stray corrosion of the dispersed electrolyte. Finally, the experimental results show that the ruled surface blade with a machining taper of 0.93° and blade surface roughness of 0.566 μm can be successfully obtained using a 50° tapered cathode sheet with a micro-grooves structure. This study provides an effective process that can be used for the ECM of ruled surface parts with high precision and good quality, and in the future this process can be extended to machining space complex surface parts.