Improvement on the periodic dissolution behavior of titanium alloy in counter-rotating electrochemical machining

Counter-rotating electrochemical machining is an effective method for machining thin-walled revolving parts with concave-convex structures. In this process, the anode workpiece and cathode tool rotate oppositely at the same rotational speed, and the material is dissolved under a periodic machining current with long off-time. This special periodic current results in serious pitting corrosion when a titanium alloy workpiece is involved. An experimental system with a programmable power supply has been developed to understand the periodic dissolution behavior. An auxiliary electrode with positive potential near workpiece is proposed to prevent the pitting corrosion. Experimental results indicate that the surface quality is improved remarkably.